(a) A courier company advertises that at least 90% of all packages brought to its office in the morning for delivery within the same city will be delivered by 5pm on the same day. Due to recent...

Extracted text: (a) A courier company advertises that at least 90% of all packages brought to its office in the morning for delivery within the same city will be delivered by 5pm on the same day. Due to recent customer complaints, the Consumer Complaint Management Centre has set up a task force to investigate the company's claim. (i) Let p denote the true proportion of packages that are delivered as advertised. Set up the hypotheses for the investigation. (ii) Describe the type I and II errors in the context of this problem situation. (iii) Which type of error is more serious for the courier company? Why? (b) Explain why the smaller the significance level, the harder it is for a null hypothesis to be rejected.