WISKUNDE
GRAAD 10
NOG OEFENINGE
  
Statistiek : antwoorde.
  
  
MATHEMATICS
GRAAD 10
NOG OEFENINGE
  
Statistics : answers.
  
  

    
Antwoord / Answer 1.

  1.1   Stingel / Stem    Blaar / Leave
  
                    2                  5;  6;  7      
  
                    3                  4
  
                    4                  5;  7;  7;      
  
                    5                  3
  
                    6                  2;  8
  
                    7                  5
  
                    8                  3;  4
  
                         Vr. / Qu. 1.1

  
  
                                                   Σ x            676
1.2.1  Gemiddelde / Mean  =  ────    =  ───       
                                                     n              13
  
                                            =  52                            Vr. / Qu. 1.2.1
  
  
1.2.2  Modus / Mode  =  47   (2 keer / twice)           Vr. / Qu. 1.2.2
  
  
  
  
1.2.3  Omvang / Range  =  maks. / max  − min.
  
  
  
                                        =  84  −  25
  
                                        =  59                                Vr. / Qu. 1.2.3
  
  
     1.2.4  Lys die getalle van klein na groot.  /  List the numbers is ascending order :
  
                     25       26       27       34       45       47       47       53       62       68       75       83       84
  
                                                Q1                                  Q2                                 Q3
  
             Q2 is die middelste getal.  /  Q2 is the number exactly in the middle.
  
              Q2  =  47
  
             OF / OR  met die formule: / using the formulae :
  
                                                                      2(n + 1)           2(13 + 1)           2 × 14
                  Posisie van / Position of Q2  =  ──────    =   ──────    =   ─────   = 7
                                                                           4                       4                    4
  
              Q2  is die 7de getal / Q2  is the 7th number  d.i. / i.e.  Q2   =  47                            Vr. / Qu. 1.2.4
  
    
  1.2.5   Q1 verdeel die linkerkantse helfte van die getalle in die helfte,  /  Q1 divides the lefthand half into two equal parts.
  
             Q1 is die getal halfpad tussen 27 en 34, die gemiddelde van 27 en 34.  /  
             Q1 is the number halfway between 27 and 34, i.e. the average of 27 and 34.
  
                           27 + 34
             Q1  =  ──────   =  30,5
                               2
  
             Q3 verdeel die regterkantse helfte van die getalle in die helfte,     /  
             Q3 divides the righthand half into two equal parts.
  
             Q3 is die getal halfpad tussen 68 en 75, die gemiddelde van 68 en 75.  /  
             Q3 is the number halfway between 68 and 75, i.e. the average of 68 and 75.
  
                           68 + 75
             Q3  =  ──────   =  71,5
                               2
  
             OF / OR  gebruik die formules: / use the formulae :
  
                                                                  (n + 1)                                                                      3(n + 1)
            Posisie van / Position of Q1  =  ──────                 Posisie van / Position of Q3  =  ──────
                                                                     4                                                                                 4
  
                                                                (13 + 1)                                                                     3(13 + 1)
                                                          =  ──────                                                               =  ──────
                                                                     4                                                                                 4
  
                                                                14                                                                                3 × 14
                                                          =  ───    =  3,5                                                          =   ─────   = 10,5
                                                                 4                                                                                    4
  
              Q1  is die 3de getal, 27, plus die helfte van die verskil tussen die derde getal (27) en die vierde getal (34)   /
                 Q1  is the 3rd number, 27, plus half of the difference between the third number (27) and the fourth number (34)
  
                                       34 − 27
              Q1  =  27  +  ──────  =  30,5
                                            2
              Q3  is die 10de getal, 68, plus die helfte van die verskil tussen die tiende getal (68) en die elfde getal (75)  /
               Q3  is the 10th number, 28, plus half of the difference between the tenth number (68) and the eleventh number (75)
  
                                        75 − 68
              Q3  =  68  +  ──────  =  71,5
                                            2                                                             Vr. / Qu. 1.2.5

  
    
  1.2.6  IKVW / IQR  =  Q3  −  Q1  =  71,5  −  30,5  =  41                 Vr. / Qu. 1.2.6
   
  1.3   Vyfpuntopsomming / Five number summary :
  
          Minimum = 25;     Q1 = 30,5;     Q2 = 47;     Q3 = 71,5;     maksimum / maximum = 86                 Vr. / Qu. 1.3
  
  1.4       
  
  
  
  
  
  
  
  
                                                          Vr. / Qu. 1.4

    
Antwoord / Answer 2.

  2.1   Stingel / Stem    Blaar / Leave
  
                    14                  8;          
  
                    15                  1;  4;  5;  7;  9    
  
                    16                  3;  3;  7;      
  
                    17                  2;  2;  2;  3;
  
                    18                  2;  4
  
                        Vr. / Qu. 2.1
  
  
  
  
                                                   Σ x            2 427
2.2.1  Gemiddelde / Mean  =  ────    =  ───       
                                                     n              15
  
                                            =  164,8                           Vr. / Qu. 2.2.1
  
  
2.2.2  Modus / Mode  =  172   (3 keer / thrice)            Vr. / Qu. 2.2.2
  
  
2.2.3  Omvang / Range  =  maks. / max  − min.       
  
                                        =  184  −  148
  
                                        =  36                                    Vr. / Qu. 2.2.3
  
  
  2.2.4  Lys die getalle van klein na groot.  /  List the numbers is ascending order :
  
             148     151     154     155     157     159     163     163     167     172     172     172     173     182     184
  
                                         Q1                                             Q2                                 Q3
  
             Q2 is die middelste getal.  /  Q2 is the number exactly in the middle.
  
              Q2  =  163
  
             OF / OR  met die formule: / using the formulae :
  
                                                                      2(n + 1)           2(15 + 1)           2 × 16
                  Posisie van / Position of Q2  =  ──────    =   ──────    =   ─────   = 8
                                                                           4                       4                    4
  
              Q2  is die 8ste getal / Q2  is the 8th number  d.i. / i.e.  Q2   =  163                          Vr. / Qu. 2.2.4
  
  
  
  2.2.5   Q1 verdeel die linkerkantse helfte van die getalle in die helfte.      /  Q1 divides the lefthand half into two equal parts.
  
             Q1 is die vierde getal, d.i. Q1 = 155.  /  Q1 is the fourth number, i.e. Q1 = 155.
  
             Q3 verdeel die regterkantse helfte van die getalle in die helfte,  /  Q3 divides the righthand half into two equal parts.
  
             Q3 is die 12de getal, d.i. Q3 = 172  /  Q3 is the 12th number, i.e. Q3 = 172.
  
  
  
             OF / OR  gebruik die formules: / use the formulae :
  
                                                                   (n + 1)                                                                             3(n + 1)
              Posisie van / Position of Q1  =  ──────                       Posisie van / Position of Q3  =  ──────
                                                                       4                                                                                       4
  
                                                                 (15 + 1)                                                                            3(15 + 1)
                                                           =  ──────                                                                      =  ──────
                                                                      4                                                                                        4
  
                                                                 16                                                                                      3 × 16
                                                           =  ───    =  4                                                                    =   ─────   = 12
                                                                  4                                                                                           4
  
              Q1  is die 4de getal, 155  /   Q1  is the 4th number, 155
  
              Q3  is die 12de getal, 172  /   Q3  is the 12th number, 172                                                      Vr. / Qu. 2.2.5
  
  
  2.2.6  IKVW / IQR  =  Q3  −  Q1  =  71,5  −  30,5  =  41                                                                         Vr. / Qu. 2.2.6
  
  2.3   Vyfpuntopsomming / Five number summary :
  
          Minimum = 25;     Q1 = 30,5;     Q2 = 47;     Q3 = 71,5;     maksimum / maximum = 86              Vr. / Qu. 2.2.6
  
  2.4       
  
  
  
  
  
  
  
  
                                                         Vr. / Qu. 2.4

    
Antwoord / Answer 3.

  3.1   Stingel / Stem    Blaar / Leave
  
                    1                  6;  8;  9      
  
                    2                  0;  1;  2;  3;  4;  8;  9
  
  
  
  
                        Vr. / Qu. 3.1
  
  
  
  
  
  
  
  
                                                   Σ x            220
3.2.1  Gemiddelde / Mean  =  ────    =  ───       
                                                     n              10
  
                                            =  22                                Vr. / Qu. 3.2.1
  
  
3.2.2  Modus / Mode  =  geen / no   
           (al die getalle kom net een keer voor / 
  
           (all the numbers have a frequency of 1)          Vr. / Qu. 3.2.2
  
  
3.2.3  Omvang / Range  =  maks. / max  − min.       
  
                                        =  29  −  16
  
                                        =  13                                    Vr. / Qu. 3.2.3
  
  
  3.2.4  Lys die getalle van klein na groot.  /  List the numbers is ascending order :
  
                     16       18       19       20       21       22       23       24       28       29
  
  
                                                                (n + 1)              (10 + 1)              11
            Posisie van / Position of Q1  =  ──────    =   ──────    =   ─────   = 2,75
                                                                    4                        4                    4
  
              Q1  =  getal 2 + 0,75(getal 3 − getal 2)  /  number 2  +  0,75(number 3 − number 2)
  
                        =  18 + 0,75(19 − 18)    =  18,75
  
                                                                      2(n + 1)           2(10 + 1)           2 × 11
                  Posisie van / Position of Q2  =  ──────    =   ──────    =   ─────   = 5,5
                                                                           4                       4                    4
  
              Q2  =  getal 5 + 0,5(getal6 − getal5)  /  number5  +  0,5(number6 − number5)
  
                        =  21 + 0,5(22 − 21)    =  21,5
  
                                                                      3(n + 1)           3(10 + 1)           3 × 11
                  Posisie van / Position of Q3  =  ──────    =   ──────    =   ─────   = 8,25
                                                                           4                       4                    4
  
              Q3  =  getal 8 + 0,25(getal 9 − getal 8)  /  number 8  +  0,25(number 9 − number 8)
  
                        =  24 + 0,25(28 − 24)    =  25                                                                                           Vr. / Qu. 3.2.4
  
  3.2.5  IKVW / IQR  =  Q3  −  Q1  =  25  −  18,75  =  6,25                                                                      Vr. / Qu. 3.2.5
  
  3.3   Vyfpuntopsomming / Five number summary :
  
          Minimum = 16;     Q1 = 18,75;     Q2 = 21,5;     Q3 = 25;     maksimum / maximum = 29            Vr. / Qu. 3.3
  
  3.4       
  
  
  
  
  
  
  
  
                                                    Vr. / Qu. 3.4

    
Antwoord / Answer 4.

  4.1   Stingel / Stem    Blaar / Leave
  
                    3                  8
  
                    4                  3;  5;  8
  
                    5                  1;  2;  3  4;  6;  8
  
                    6                  1;  2;  3;  5
  
                    7                  1;  2
  
                          Vr. / Qu. 4.1
  
  
4.2.1  Omvang / Range  =  maks. / max  − min.       
  
                                        =  72  −  38
  
                                        =  34                                  Vr. / Qu. 4.2.1
  
  
  
  
  

  
  

  4.2.2  Lys die getalle van klein na groot.  /  List the numbers is ascending order :
  
                     38       43       45       48       51       52       53       54       56       58       61       62       63       65       71       72
  
  
                                                                       (n + 1)              (16 + 1)              17
                  Posisie van / Position of Q1  =  ──────    =   ──────    =   ─────   = 4,25
                                                                           4                       4                    4
  
              Q1  =  getal 4 + 0,25(getal 5 − getal 4)  /  number 4  +  0,25(number 5 − number 4)
  
                        =  48 + 0,25(51 − 48)    =  48,75
  
                                                                      2(n + 1)           2(16 + 1)           2 × 17
                  Posisie van / Position of Q2  =  ──────    =   ──────    =   ─────   = 8,5
                                                                           4                       4                    4
  
              Q2  =  getal 8 + 0,5(getal9 − getal8)  /  number8  +  0,5(number9 − number8)
  
                        =  54 + 0,5(56 − 54)    =  55
  
                                                                      3(n + 1)           3(16 + 1)           3 × 17
                  Posisie van / Position of Q3  =  ──────    =   ──────    =   ─────   = 12,75
                                                                           4                       4                    4
  
              Q3  =  getal 12 + 0,75(getal 13 − getal 12)  /  number 12  +  0,75(number 13 − number 12)
  
                        =  62 + 0,75(63 − 62)    =  62,75                                                                                     Vr. / Qu. 4.2.2
  
  
  4.2.3  IKVW / IQR  =  Q3  −  Q1  =  62,75  −  48,75  =  14                                                                  Vr. / Qu. 4.2.3
  
  
  4.3   Vyfpuntopsomming / Five number summary :
  
          Minimum = 16;     Q1 = 18,75;     Q2 = 21,5;     Q3 = 25;     maksimum / maximum = 29          Vr. / Qu. 4.3
  
  
  4.4       
  
  
  
  
  
  
  
  
                                                      Vr. / Qu. 4.4
  

Antwoord / Answer  5

      omvang / range = maksimum / maximum  −  minimum
      a = minimum =  38 − 24
                            = 14
      d = Q3  =  2 × minimum
         = 2 × 14   = 28
      IKVW / IQR = Q3 − Q1
      b = Q1  =  Q3 − IKVW / IQR    
         = 28 − 8 = 20
      c = Q2  =  Q1 + 4
         = 20 + 4 = 24
  
      a = 14;    b = 20;    c = 24;    d = 28;    e = 38
  
Vraag / Question 5.


Antwoord / Answer  6

      omvang / range = maksimum / maximum  −  minimum
      36 = e  −  18
      e = 36 + 18   =  54
      c = Q2  =  e − 18
                    = 54 − 18   = 36
      d = Q3  =  Q2 + 6
         = 36 + 6 = 42
      IKVW / IQR = Q3 − Q1
      b = Q1  =  Q3 − IKVW / IQR
          = 42 − 11 = 31
  
      a = 18;    b = 31;    c = 36;    d = 42;    e = 54
  
Vraag / Question 6.


Antwoord / Answer  7.

      omvang / range = maksimum / maximum  −  minimum
      32 = e  −  33
      e = 32 + 33   =  65
      c = e − 12
         = 65 − 12   = 53
      d = 2a − 4
         = 2 × 33 − 4   = 62
      b = d − 20
         = 62 − 20   = 42
  
      a = 33;    b = 42;    c = 53;    d = 62;    e = 65
  
Vraag / Question 7.


Antwoord / Answer  8

      8.1  25%
  
      8.2  50%
  
      8.3  omvang / range  =  68 − 4    = 64
  
  
      8.4  IKVW / IQR = Q3 − Q1
                         =  50  −  32    =  18
  
  
  
Vraag / Question 8.


Antwoord / Answer  9.

    9.1  
  
  
  
Klas middelpunt (x)
Class midpoint (x)
Frekwensie f
Frequency
f . x
0 ≤ m < 10
5
2
  10
10 ≤ m < 20
15
6
  90
20 ≤ m < 30
25
12
300
30 ≤ m < 40
35
15
525
40 ≤ m ≤ 50
45
10
450

  
                                                   Σfx               1 375
    9.2  gemiddelde / mean  =  ────    =    ─────  =    30,56
                                                    n                    45
  
  
  
  
    9.3  modale klas / 
           modal class  =  30  ≤  m  <  40     ( f = 15 )
  
  
  
  
  
                                                                     n
    9.4.1  Posisie van / Position of  Q2   =  ───
                                                                     4
  
                                                                       45
                                                              =    ────
                                                                        4
  
                                                              =  11,25
              Q2  is die 12de getal en dus in die
              interval  20 ≤ m < 30  /
              Q2  is the 12th number and thus in
              the interval  20 ≤ m < 30
  
  
                                                                    3n
    9.4.3  Posisie van / Position of  D3   =  ───
                                                                    10
  
                                                                  3 × 45
                                                             =  ─────
                                                                    10
  
                                                             =  13,5
              Die derde desiel is die 14de getal en is
              in die interval  20 ≤ m < 30  /
  
              The third decile is the 14th number and thus
               in the interval  20 ≤ m < 30
  
  
                                                                    70n
    9.4.2  Posisie van / Position of  P70   =  ───
                                                                    100
  
                                                                    70 × 45
                                                               =  ──────
                                                                       100
  
                                                               =  31,5
              Die 70ste  persentiel is die 32ste getal en is
              in die interval  30 ≤ m < 40  /
  
              The 70th  percentile is the 32nd number and thus
               in the interval 30 ≤ m < 40
  
  
  
  
  
  
  
  
  
  
  

Antwoord / Answer  10.

    10.1  
  
  
  
Klas middelpunt (x)
Class midpoint (x)
Frekwensie f
Frequency
f . x
40 ≤ m < 50
45
6
180
50 ≤ m < 60
55
11
550
60 ≤ m < 70
65
9
595
70 ≤ m < 80
75
2
150

  
                                                    Σfx               1 610
    10.2  gemiddelde / mean  =  ────    =    ─────  =    57,5
                                                    n                    28
  
  
  
  
    10.3  modale interval / 
             modal interval  =  50  ≤  m  <  60     ( f = 11 )
  
  
  
  
  
                                                                     2n
    10.4.1  Posisie van / Position of  Q2   =  ───
                                                                      4
  
                                                                      2 × 28
                                                                =  ─────
                                                                          4
  
                                                                =  14
              Q2  is die 14de getal en dus in die interval
                  50 ≤ m < 60  /
              Q2  is the 14th number and thus in the interval
                   50 ≤ m < 60
  
  
                                                                     2n
    10.4.3  Posisie van / Position of  D2   =  ───
                                                                      10
  
                                                                      2 × 28
                                                                =  ─────
                                                                        10
  
                                                                =  5,6
              D2  is die 6de getal en dus in die interval
                  40 ≤ m < 50  /
              D2  is the 6th number and thus in the interval
                   40 ≤ m < 50
  
  
                                                                     80n
    10.4.2  Posisie van / Position of  P80   =  ───
                                                                      100
  
                                                                     80 × 28
                                                                =  ─────
                                                                       100
  
                                                                =  22,4
              P80  is die 23ste getal en dus in die interval
                  60 ≤ m < 70  /
              P80  is the 23rd number and thus in the interval
                   60 ≤ m < 70
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  

Antwoord / Answer  11.

    11.1  
  
Lengte  h (cm)
Height
Frekwensie f
Frequency
Klas middelpunt (x)
Class midpoint
   f . x   
120 ≤ h < 140
4
130
    520
140 ≤ h < 160
15
150
 2 250
160 ≤ h < 180
10
170
 1 700
180 ≤ h < 200
3
190
    570

  
                                                    Σfx               5 040
    11.2  gemiddelde / mean  =  ────    =    ─────  =    157,5
                                                    n                    28
  
  
  
  
    11.3  modale interval / 
              modal interval  =  140  ≤  h  <  160     ( f = 15 )
  
  
  
  
    11.4.1  Die gemiddelde is in die interval 140 ≤ h < 160 /
  
                The mean is in the interval   140  ≤  h  <  160
  
  
                                                                      3n
    11.4.3  Posisie van / Position of  Q3   =  ───
                                                                       4
  
                                                                        3 × 32
                                                                =  ──────
                                                                            4
  
                                                                =  24
              Q3  is die 24ste getal en dus in die 
              interval  160 ≤ h < 180  /
              Q3  is the 24th number and thus in the 
              interval  160 ≤ h < 180
  
  
                                                                      8n
    11.4.5  Posisie van / Position of  D8   =  ───
                                                                      10
  
                                                                   8 × 32
                                                             =  ─────
                                                                     10
  
                                                             =  25,6
              D8  is die 26ste getal en dus in die 
              interval  160 ≤ h < 180  /
              D8  is the 26th number and thus in the 
              interval  160 ≤ h < 180
  
  
                                                                       n
    11.4.2  Posisie van / Position of  Q1   =  ───
                                                                       4
  
                                                                       32
                                                                =  ───
                                                                       4
  
                                                                =  8
              Q1  is die 8ste getal en is in
              die interval  140 ≤ h < 160  /
              Q1  is the 8th number and thus 
              in interval  140 ≤ h < 160
  
  
                                                       30n
    11.4.4  Posisie van / P30   =  ───
                                                       100
  
                                                   30 × 32
                                              =  ─────
                                                     100
  
                                              =  9,6
              P30  is die 10de waarde en is in die
              interval  140 ≤ h < 160  /
              P30  is the 10th value and thus 
              in interval  140 ≤ h < 160
  
  
  
  
  
  
  
      11.5  Die aantal dogters is 19  /  There are 19 girls.
  
  
Vraag / Question 11.
  

Antwoord / Answer  12.

    12.1  
  
Tyd t (minute)
Time
Frekwensie f
Frequency
Klas middelpunt (x)
Class midpoint
   f . x   
  5 ≤ t < 10
1
    7,5
  7,5
10 ≤ t < 15
5
12,5
  62,5
15 ≤ t < 20
8
17,5
140
20 ≤ t < 25
4
22,5
  90
25 ≤ t < 30
2
27,5
  55

  
                                                    Σfx               355
    12.2  gemiddelde / mean  =  ────    =    ─────  =    17,75
                                                    n                    20
  
  
  
  
    12.3  modale interval / modal interval  =  15  ≤  t  <  20
                             ( f = 8 )
  
  
  
  
  
                                                                       n
    12.4.1  Posisie van / Position of  Q1   =  ───
                                                                       4
  
                                                                      20
                                                                =  ───
                                                                       4
  
                                                                =  5
              Q1  is die 5de waarde en is in
              die interval  10 ≤ t < 15  //
              Q1  is the 5th value and thus in 
              interval  10 ≤ t < 15
  
  
                                                                      4n
    12.4.3  Posisie van / Position of  D4   =  ───
                                                                      10
  
                                                                      4 × 16
                                                                =  ─────
                                                                        10
  
                                                                =  6,4
              D4  is die 7de waarde en is in
              die interval  15 ≤ t < 20  /
              D4  is the 7th value and thus 
              in interval  15 ≤ t < 20
  
                                                                        80n
    12.4.2  Posisie van / Position of  P80   =  ────
                                                                       100
  
                                                                        80 × 20
                                                                 =  ───────
                                                                           100
  
                                                                 =  16
              P80  is die 16de waarde en is in
              die interval  20 ≤ t < 25  /
              P80  is the 16th value and thus in 
              interval  20 ≤ t < 25