A consultant is tasked with studying the purchasing habits of customers in an Indonesian coffee shop

A consultant is tasked with studying the purchasing habits of customers in an Indonesian coffee shopwhich specialises in Kopi Luwak. They select a random sample of 70 customers during a certain week and

which specialises in Kopi Luwak. They select a random sample of 70 customers during a certain week andfind that the mean amount spent was 287,000 rupiah, with a standard deviation of 62,000 rupiah. They

find that the mean amount spent was 287,000 rupiah, with a standard deviation of 62,000 rupiah. Theyalso found that 32 customers would 'strongly recommend' the coffee shop to their family and friends.

also found that 32 customers would 'strongly recommend' the coffee shop to their family and friends.

(a) At the 0.05 level of significance, is their evidence that the population mean amount spent was

(a) At the 0.05 level of significance, is their evidence that the population mean amount spent wasdifferent from 265,000 rupiah? Show all your working and clearly indicate the assumptions used.

different from 265,000 rupiah? Show all your working and clearly indicate the assumptions used.

(b) At the 0.05 level of significance, is there evidence that more than 50% of all the customers say they

(b) At the 0.05 level of significance, is there evidence that more than 50% of all the customers say theywould 'strongly recommend' the coffee shop to their family and friends? Show all your workings and

would 'strongly recommend' the coffee shop to their family and friends? Show all your workings andassumptions used.