1. According to Money, the average price of a home in Albuquerque is $165,000.6 Suppose that the reported ?gure is a sample estimate based on 80 randomly chosen homes in this city, and that the population standard deviation was known to be $55,000. Give an 80% con?dence interval for the population mean home price.
2. A mining company needs to estimate the average amount of copper ore per ton mined. A random sample of 50 tons gives a sample mean of 146.75 pounds. The population standard deviation is assumed to be 35.2 pounds. Give a 95% con?dence interval for the average amount of copper in the "population" of tons mined. Also give a 90% con?dence interval and a 99% con?dence interval for the average amount of copper per ton.
3. A new low-calorie pizza introduced by Pizza Hut has an average of 150 calories per slice. If this number is based on a random sample of 100 slices, and the population standard deviation is 30 calories, give a 90% con?dence interval for the population mean.