QUESTION 3 [60] An investigator wishes to estimate the amount spend on grocery at a certain supermarket on a Sunday afternoon. A random sample of customers was selected and the following data was obtained: 1500 1800 1400 900 700 2500 4000 3500 2000 1600 1200 700 1600 1900 500 2500 (i) Estimate the average amount spend on grocery using a 95% confidence interval. (20) (ii)Suppose the operations manager of the grocery supermarket claims that customers spend on average N$ 1500 on Sunday afternoons. Apply the critical value approach to test the manager's claim at 10% level of significance. (20) (iii) Suppose the operation manager of the grocery supermarket further claims that 60% of the customers spend at least N$ 1500 on Sunday afternoons. Apply the p-value approach to test the manager's claim at 1% level of significance. (