9-10. The average precipitation for the first seven months of the year is 19.32 inches with a standard deviation of 2.4 inches. Assume the average precipitation is normally distributed. 9. What is the probability that a randomly selected year will have a precipitation greater than 18 inches for the first 7 months? a. 0.7088 b. 0.8523 c. 0.4562 d. 0.1258 10. What is the probability of 5 randomly selected years will have an average precipitation greater than 18 inches for the first 7 months? a. 0.8907 b. 0.2587 c. 0.4156 d. 0.2879 1 1. Which of the following is a parameter? a. X b. X C. u d. Z 12. Which of the following best represents the central value of a set of data? a. variance b, average c. proportion d. standard deviation 13. What do you call a single value that may refer to a parameter value? a. z statistic b. t statistic c. point estimate d. interval estimate 14. The is a range of values that contains the parameter value. a. confidence limits b. confidence interval c. confidence coefficient d. confidence level 15. Which of the following are the 95% confidence coefficients (one-tailed)? A. +1.645 B. $1.96 C. +2.33 D. 12.58 16. When n