Statistics Revision Paper 4 & 5

STATISTICS - REVISION PAPER 4


Table 1 - distribution of results by students in an exam

Mark 0-20 21-40 41-60 61-80 81-100
Frequency 2 9 26 18 7

Table 2 – phone calls recorded in a company

Time (mins) 0-10 10-20 20-30 30-40 40-50
No. of calls 11 22 34 22 11

Table 3 –

x 15 13 17 19 14 16 14 14 15 18
y 7 4 9 8 7 7 4 6 4 7


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 56.61
b 370.71
c 19.25

2a 55
b 44
c 69

3a 25
b 25

4a 0.69
b 0.76