a. A delivery service claims that 85% of their customers will receive their order within the advertised time. A competitor wishes to test if the proportion of customers who receive their order within the advertised time is less than this and conducts a survey on a random sample of 40 customers who use this delivery service. The competitor finds that the proportion of customers who receive their order within the advertised time is actually 72%. You are asked to conduct a hypothesis test at a 5% level of significance to determine if the proportion of customers who receive their order within the advertised time is less than what the delivery service claims. i. State the hypothesis statements. [1] ii. Find the test statistic. [2] iii. What is the critical value? [1] iv. Write down the decision, clearly stating the reason. [1] v. What is the conclusion? [1]