Question

1) A statistics teacher started class one day by drawing the names of n = 16 students out of a hat and asked them to do as many pushups as they could. The 16 randomly selected students averaged 15.2 pushups per person with a standard deviation of 8.5 pushups. Suppose the distribution of the population of number of pushups that can be done is approximately normal.

The 95% confidence interval for the true mean number of pushups that can be done is

2) The CEO of a company wants to estimate the percent of employees that use company computers to go on Facebook during work hours with 95% confidence. He selects a random sample of n = 225 of the employees and finds that 63 of them logged onto Facebook that day. What is the point estimate of the proportion of the population that logged onto Facebook that day?

3)A mail-order business prides itself in its ability to fill customers' orders in less than 6 calendar days, on average. Periodically, the operations manager selects a random sample of customer orders and determines the number of days required to fill the orders. On one occasion when a sample of 39 orders was selected, the average number of days was 6.65 with a sample standard deviation of 1.5 days. Calculate the appropriate test statistic to test the hypothesis that the mean is equal to six. 

Answer 1