QUESTION FOUR

(a) Three suppliers provide the following data on defective spare parts.

Supplier Part Quality

Good Minor Defect Major Defect

A 90 3 7

B 170 18 7

C 135 6 9

1. use =0.05 and test for independence between supplier and spare part quality
2. What does the result of your analysis tell the purchasing department?

(b) A new fly spray is applied to 50 samples each of 5 flies and the number of living flies counted after an hour. The results were as follows:

Number Living 0 1 2 3 4 5

Frequency 7 20 12 9 1 1

1. Calculate the mean number of living flies per sample and hence an estimate for p ,the probability of a fly surviving the spray
2. Using your estimate calculate the expected frequencies (each correct to one decimal place) corresponding to a binomial distribution
3. Perform a chi - square goodness - of - fit test using a 5% significance level.

(c) A worker earned K11, 800 per month in 2016. The cost of living index increased by 63.8% between 2016 and 2019. How much extra income should the worker have earned in 2019 so that he could buy the same quantities as in 2016?