PLEASE HELP

(a) (b) (C) Qick Express is responding to criticisms from customers about late delivery of parcels by initiating new procedures to alleviatethis problem. They have been assured that this change would result in a late rate of 10 percent. After 6 months of using the suggested new procedures, Qick Express decided to conduct an investigation into the late delivery claim by posting 21 parcels to various parts of the country. 5 parcels arrived late at their destinations. Calculate the estimate of the proportion of the parcels that arrived late. Then construct and interpret a 95 percent confidence interval for the population proportion of parcels that were delivered late. [6 marks] Without further calculations, at 5 percent significance level, can the Operations Manager conclude that the new procedures are alleviating the problem of late delivery of parcels? [2 marks] Without further calculations, if the confidence interval changes from 95 percent to 90 percent, what would happen to the interval? [2 marks] Explain why a 95 percent confidenceinterval can be used in hypothesis (d) testing at 5 percent significance level. [3 marks]