Answer to Question #60656 in Statistics and Probability for esita

Question

a) The distribution of marks obtained by 500 candidates in a particular exam is given
below:

Marks more than: 0 10 20 30 40 50
Number of candidates 500 460 400 200 100 30

Calculate the lower quartile marks. If 70% of the candidates pass in the exam, find
the minimum marks obtained by a pass candidate. (5)
b) An analysis of monthly wages paid to the workers of two firms A and B belonging
to the same industry gives the following results:

Firm A Firm B
Number of workers 500 600
Average daily wages ` 186 ` 175
Variance of distribution of wages 81 100

i) Which firm, A or B, has a large wage bill?
ii) In which firm, A or B, is there greater variability in individual wages?
iii) Find the average daily wage and the variance of the distribution of wages of all
the workers in the firms A and B taken together.