Business Stats Ch. 9 Test Bank Study Guide Graded A+

A sample standard deviation is the best point estimate of the ___________. {Ans: population standard deviation}A survey of an urban university (population of 25,450) showed that 870 of 1,100 students sampled supported a fee increase to fund improvements to the student recreation center. Using the 99% level of confidence, what is the confidence interval for the proportion of students supporting the fee increase? {Ans: [0.759, 0.823]}A student wanted to construct a 99% confidence interval for the mean age of students in her statistics class. She randomly selected nine students. Their mean age was 19.1 years with a sample standard deviation of 1.5 years. What is the 99% confidence interval for the population mean? {Ans: [17.42, 20.78]}The distribution of Student's t has _________. {Ans: a mean of zero and a standard deviation that depends on the sample size}A survey of 25 grocery stores revealed that the mean price of a gallon of milk was $2.98, with a standard error of $0.10. What is the 95% confidence interval to estimate the true cost of a gallon of milk? {Ans: $2.77 to $3.19}A survey of an urban university (population of 25,450) showed that 750 of 1,100 students sampled