In a Singapore Edition of Business Times, diamond pricing we explored. The price of a diamond is based on the diamond's weight, color, and clarity. A Simple random sample of 18 one-half-carat diamonds had the following prices, in dollar's:
1676 1442 1995 1718 1826 2071 1947 1983 2146
1995 1876 2032 1988 2071 2234 2108 1941 2316
Based on the above information, solve the following problems:
a. Apply the t-interval procedure to these data to find a 90% confidence interval for the mean price of all one-half-carat diamonds. Interpret your result. (Note: X-bar = $1964.7 and s = $206.5.)
b. Based on your graphs from part (b), is it reasonable to apply the t-interval procedure as you did in part a? Explain your answer.