Refer to Exercise 8.24. A city planner wants to estimate, with a 97% confidence level, the average monthly residential water usage in the city. Based on earlier data, the population standard deviation of the monthly residential water usage in this city is 389.60 gallons. How large a sample should be selected so that the estimate for the average monthly residential water usage in this city is within 100 gallons of the population mean?
Answer to relevant QuestionsYou are interested in estimating the mean commuting time from home to school for all commuter students at your school. Briefly explain the procedure you will follow to conduct this study. Collect the required data from a ...What assumptions must hold true to use the t distribution to make a confidence interval for µ? a. Find the value of t from the t distribution table for a sample size of 22 and a confidence level of 95%. b. Find the value of t from the t distribution table for 60 degrees of freedom and a 90% confidence level. c. Find ...A random sample of 16 airline passengers at the Bay City airport showed that the mean time spent waiting in line to check in at the ticket counters was 31 minutes with a standard deviation of 7 minutes. Construct a 99% ...The following data give the speeds (in miles per hour), as measured by radar, of 10 cars traveling on Interstate I-15: Assuming that the speeds of all cars traveling on this highway have a normal distribution, construct a ...
Post your question