Q1. Suppose that the medium coffees sold by a certain coffee shop have a mean volume of 16 ounces and a standard deviation of 0.4 ounces. What is the probability that a random sample of 100 medium coffees sold by that shop has a total volume of less than 1603 ounces?
Q2. The total evaporation amount of a growing season in Minneapolis is approximately normally distributed with a standard deviaion of 4.00 inches. Given that the most recent 16 growing seasons have an average evaporation amount of 34.50 inches, find a 95% confidence interval for the population mean of the growing season evaporation amount in Minneapolis.
Q3. Historically, the precipitation of July in Twin Cities (in inches) approximately follows a normal distribution with a mean μ = 3.57 and a variance σ2 = 6.14. Would you still consider σ2 = 6.14 a valid value of the variance given that the sample variance for the precipitation of July in Twin Cities during the most recent 30 years is s2 = 11.08?
Q4. Let X denote the number of days with snowfall of at least 1 inch in a winter. During the past 121 winters, Twin Cities, MN has observed a mean of X‾Tc = 14.4 days and a sample standard deviation of sTc = 5.27 days; during the past 61 winters, Eau Claire, WI has observed a mean of X‾Ec = 14.9 days and a sample standard deviation of sEc = 5.20 days. Assume that the data from Twin Cities and Eau Claire are independent. Construct a 90% confidence interval for σTc/σEc, where σTc and /σEc How are the population standard deviations for Twin Cities and Eau elaire, respectively.