. Many people take ginkgo supplements advertised to improve memory. Are these over-the-counter supplements effective? In a study reported in the paper "Ginkgo For Memory Enhancement" elderly adults were assigned at random to either a treatment group or a control group. 104 participants took gingko and 111 took a placebo (fake pill). At the end of six weeks a memory test was administered. In this test, a higher score means better memory function. The following table shows the results. Sample Sample Sample Size Mean Standard Deviation Ginkgo 104 5.6 0.6 Placebo 111 5.5 0.6 (5 marks). Make the 99% confidence interval for the difference in mean values in memory test score. Do pool the standard deviations. The degrees of freedom is 212 (use 200 for degrees of freedom in Table IV). (3 marks). Suppose we wished to test the hypothesis that the mean values in memory test scores are the same. Write down the appropriate null and alternative hypothesis. If we tested at 99%, use the confidence interval of part (a) to make a conclusion. explain how you can reach this conclusion. actually perform the hypothesis test.