21. Which of the following is a continuous dem var the number of new accounts established a salesperson in b. The number of customers in Rie Nick's barber shop. c. The time between sustomer arrivals to a bank ATM d. The number of minorities on a jury. e. All of the above. you 20 Given ven that X is a normal variable with no 50 od wine of 25, find the probability that X is less than 57. a. 4192 b.-1.91 c. 91924.-1.40 .0808 22 Given that is the standard normal variable, find, if PZSC)-04 22.0160 b. -1.75 C..46 d.-2.396..4840 2 The area between the moon and a selected value under the normal curve is: a the value b. the probability between the mean and the selected value c. equal to 5 d. the mean of the normal curve e the standard deviation of the normal curve 18 Given that X is a normal variable with a mean of 30 and a standard deviation of 4, find the probability that X is greater than 37. 9599b 2157 c. 4599 d..0401 c. 2843 23 Manufacturers were subdivided into groups by volume of sales. Those with more than $100 million in sales were classified as Class A large; those from $50 to $100 million as Class A medium; and those between $25 and 550 million as Class A small and so on. Samples were then selected from each of these groups. What is this type of sampling called? a. Simple random. b. Convenience. e. Stratified random. b. Panel. d. Complicated random 2435 What is the difference between a sample mean and the population mean called? a. Standard error of the mean. c. Point estimate. e. There is no difference. b. Interval estimate. d. Sampling error. 25 26 Given that X is normal random variable, the probability that a given value of X is below its mean is: a. approximately 0. d. unknown, since the distribution might be skewed. b. approximately 1. e. unknown, since the mean and variance are unknown. ..50