[Chapter 7] Sampling Distribution A business magazine surveyed MBA alumni five years after graduation. One finding was that alumni spend an average of $120 per week eating out socially. You have been asked to conduct a follow-up study by taking a sample of 36 of these MBA alumni. Assume that the weekly expenditures of eating out for MBA alumni are normally distributed with a population standard deviation of $30. Let xbe the random variable for the weekly expenditure of eating out. Answer the following questions based on the given information. Question 2 (2 points) What is the sampling distribution of 33 ? Q It follows a t distribution with 39 degrees of freedom. 0 It follows a t distribution with 38 degrees of freedom. Q It follows a t distribution with 40 degrees of freedom. 0 It follows a normal distribution. \fQuestion 4 (2 points) What is the probability that the sample mean 5% will be with i$10 of the population mean? 0 0.9772 Q 0.9298 Q 0.9216 Q 0.9544 Question 5 (2 points) Suppose you found a sample mean of $125. The probability of finding a sample mean of $125 or more is __________ . Q 0.1894 Q 0.8413 E Screen capture - now A Screenshot taken 0 01587 Show in folder Question 4 (2 points) O 0 - 2 1 19 What is the probability that the sample meal mean? 0 0.9772 Question 6 (4 points) A bank would like to estimate the mean number of years in which 30-year mortgages are paid off. A random sample of 18 paid-off 30-year mortgages yielded a mean of 15.7 years with a standard deviation of 8.5 years. Assume that the number of years in which 30-year mortgages are paid off is normally distributed. What is the lower limit of the 90% confidence interval for the mean number of years in which the mortgages are paid off? 0 about 11.5 0 about 12.2 0 about 9.9 0 about 13.0