Statistics revision paper 2

STATISTICS - REVISION PAPER 2


Table 1 - distribution of results by students in an exam

Mark 0-25 26-45 46-64 65-85 86-100
Frequency 3 23 34 18 15

Table 2 – phone calls recorded in a company

Time (mins) 0-4 4-8 8-12 12-16 16-20
No. of calls 2 7 14 11 6

Table 3 - results obtained by two friends in six short class tests.

x 9 7 5 4 5 6
y 5 5 6 7 6 8


TASKS

1 Using the data in table 1 find the:
a) Mean
b) Variance
c) Standard deviation
2 Using the data in table 1 draw the cumulative frequency curve and find the:
a) Median
b) Lower quartile
c) Upper quartile
3 Using the data in table 2 construct a histogram and find the:
a) Mode
b) Median
4 Using the data in table 3 calculate the:
a) Product moment correlation coefficient
b) Rank correlation coefficient



ANSWERS (calculations given to 2 decimal places)

1a 58.81
b 448.14
c 21.17

2a 56
b 43
c 74

3a 10.8
b 11.14

4a - 0.57
b - 0.56