A random sample of 100 US cities yields a 90% confidence interval for the average annual precipitation in the US of 33 inches to 39 inches. Which of the following is false based on this interval? a) 90% of random samples of size 100 will have sample means between 33 and 39 inches. b) The margin of error is 3 inches. c) The sample average is 36 inches. d) We are 90% confident that the average annual precipitation in the US is between 33 and 39 inches.