18) a finance course at a business school, 6 students are randomly selected. Their mean in score on the final exam is 75, with standard deviation 8. What is the 95% confidence interval for the average class score on the final? A [66.6, 83.4] b [67.6, 82.4] c [68.6, 81.4] d [71.7, 78.3] 19) A company's average accounts receivable per customer is $132.54. After a problem in the automated accounting software is suspected, a random sample of 38 accounts reveals a sample mean of $143.55 and a sample standard deviation of $38.29. In a two-sided hypothesis test to see if the average accounts receivable has changed, the best formulation of the null hypothesis is: a The average accounts receivable is $132.54. b The average accounts receivable is $143.55. c The average accounts receivable is no longer $132.54. d None of the above. 20. 20) A company's average accounts receivable per customer is $132.54. After a problem in the automated accounting software is suspected, a random sample of 38 accounts reveals a sample mean of $143.55 and a sample standard deviation of $38.29. After running a two-sided hypothesis test of the hypothesis that the average accounts receivable has changed, the best conclusion (using a 95% confidence level) is: a There is not sufficient evidence that the average accounts receivable has changed. b The average accounts receivable is still $132.54. c The average accounts receivable has changed. D The average accounts receivable is at least $143.55. 28) The regression analysis below relates US annual energy consumption in trillions of BTUs to the independent variables "US Gross Domestic Product (GDP) in trillions of
18) in a finance course at a business school, 6 students are randomly selected. Their mean score on the final exam is 75, with standard deviation 8. What is the 95% confidence interval for the average class score on the final? A [66.6, 83.4] b [67.6, 82.4] c [68.6, 81.4] d [71.7, 78.3] 19) A company's average accounts receivable per customer is $132.54. After a problem in the automated accounting software is suspected, a random sample of 38 accounts reveals a sample mean of $143.55 and a sample standard deviation of $38.29. In a two-sided hypothesis test to see if the average accounts receivable has changed, the best formulation of the null hypothesis is: a The average accounts receivable is $132.54. b The average accounts receivable is $143.55. c The average accounts receivable is no longer $132.54. d None of the above. 20. 20) A company's average accounts receivable per customer is $132.54. After a problem in the automated accounting software is suspected, a random sample of 38 accounts reveals a sample mean of $143.55 and a sample standard deviation of $38.29. After running a two-sided hypothesis test of the hypothesis that the average accounts receivable has changed, the best conclusion (using a 95% confidence level) is: a There is not sufficient evidence that the average accounts receivable has changed. b The average accounts receivable is still $132.54. c The average accounts receivable has changed. D The average accounts receivable is at least $143.55. 28) The regression analysis below relates US annual energy consumption in trillions of BTUs to the independent variables "US Gross Domestic Product (GDP) in trillions of