The owner of Nales Texaco would like to estimate the mean nu

The owner of Nales Texaco would like to estimate the mean number of gallons of gasoline sold to his customers per visit. Assume the number of gallons sold follows the normal distribution with a population standard deviation of 3.0 gallons From his records, he selects a random sample of 36 sales and finds the mean number of gallons sold is 8.70.Construct a 95 percent confidence interval for the population mean number of gallons sold. Is it reasonable so conclude that the populations mean number of gallons sold per visit is 9 gallons? The American Sugar Producers Association wants to estimate the mean yearly sugar consumption. A sample of 81 people reveals the mean yearly consumption to be 60 pounds with a standard deviation of 27 pounds. Develop the 90 percent confidence interval for the population mean sugar consumption.

Solution

7.72 to 9.68

55.008 to 64.992