Two samples of 100 seedlings were grown with two different fertilizers. One sample had an average height of 10 inches and a standard deviation of 1 inch. The second sample had an average height of 10.5 inches and a standard deviation of 3 inches. Construct a confidence interval for the difference between the average population heights (pi - 142)
(a) At the 95% level of confidence.
(b) At the 90% level of confidence.