5. A sample of 21 statistics students had an average test score of 79.2 and standard deviation of 6.1. Use this information to construct a 90% confidence interval estimate of the population standard deviation. Round your final answer to one decimal place. (8pts) 6. CalTrans claims the average speed at 4pm on a particular freeway is faster than 62mph. When ten vehicles were observed at random for their speeds (in mph) on a particular stretch of freeway, the following data was obtained: 68, 78, 69, 61, 68, 65, 60, 64, 60, 62. Assume vehicle speed is normally distributed. a. State the hypotheses and identify the claim. (3pts) b. Calculate the test statistic and p-value. (4pts) c. State your conclusion based on the a =. 05 significance level. What does this say about CalTrans claim? (4pts)