(a) The distribution of junior workers in an institution is as follows: Clerks – 78, Drivers – 36, Typists – 44, Messengers – 52, Others – 30. Represent the above information by a pie chart.
(b) The table below shows the frequency distribution of marks scored by 30 candidates in an aptitude test.
| Marks | 4 | 5 | 6 | 7 | 8 | 9 |
| No of candidates | 5 | 8 | 5 | 6 | 4 | 2 |
Find the mean score to the nearest whole number.
Explanation
(a) Sector angle represented by the officers:
Total number of officers = 240
Clerks = (frac{78}{240} times 360° = 117°)
Drivers = (frac{36}{240} times 360° = 54°)
Typists = (frac{44}{240} times 360° = 66°)
Messengers = (frac{52}{240} times 360° = 78°)
Others = (frac{30}{240} times 360° = 45°)
(b)
| Marks (x) | 4 | 5 | 6 | 7 | 8 | 9 | Total |
| No of candidates (f) | 5 | 8 | 5 | 6 | 4 | 2 | 30 |
| (fx) | 20 | 40 | 30 | 42 | 32 | 18 | 182 |
Mean score = (frac{sum fx}{sum f})
= (frac{182}{30})
= (6.067) marks (approxeq) 6 marks to the nearest whole number.