need help

Question 2 {Unit 10} 9 marks Do not use Minitcb to answer this question. Do the calculatiom 'by hand' (using a calculator), showing your working. A guidebook claims that their suggested Walk A takes 45 minutes to complete. In order to test this claim, 18 people use the guidebook to follow the suggested route. They recorded how long, in minutes, it took each person to complete the walk. The walkers do not walk together in a group, but each walker completes the walk by themself. The results are summarised in Table 2. Table 2 Summary statistics for the time (in minutes) taken to complete Walk A by each walker Walk number sample size mean standard deviation Walk A 18 38 7 (a) What is the most appropriate version of the ttest if you want to test the null hypothesis that the underlying population mean time taken to complete the walk is what the guidebook claims it to be and the alternative hypothesis that the underlying population mean time is not what the guide claims? Justify your choice. (b) What are the number of degrees of freedom and the 5% critical value for the most appropriate t-test applied to these data?I (c) Without using Minitab, calculate a 95% condence interval for the population mean time taken to complete this walk. Your answer should be rounded to one decimal place. (d) Based on your calculated 95% condence interval, is it plausible that the underlying population mean time taken to complete the walk is 45 minutes as claimed by the guidebook? Justify your answer. [2]