Alice walks into a post office with 2 clerks. both clerks are in the midst of serving

customers, but alice is next in line. the clerk on the left takes an expo(λ1) time to

serve a customer, and the clerk on the right takes an expo(λ2) time to serve a customer. let t be the amount of time alice has to wait until it is her turn.

(a) write down expressions for the mean and variance of t, in terms of double integrals

(which you do not need to evaluate).

(b) find the distribution, mean, and variance of t, without using calculus.

Name and describe the three most important measures of central tendency. choose the correct answer below. a. the mean, sample size, and mode are the most important measures of central tendency. the mean of a data set is the sum of the observations divided by the middle value in its ordered list. the sample size of a data set is the number of observations. the mode of a data set is its highest value in its ordered list. b. the sample size, median, and mode are the most important measures of central tendency. the sample size of a data set is the difference between the highest value and lowest value in its ordered list. the median of a data set is its most frequently occurring value. the mode of a data set is sum of the observations divided by the number of observations. c. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is the product of the observations divided by the number of observations. the median of a data set is the lowest value in its ordered list. the mode of a data set is its least frequently occurring value. d. the mean, median, and mode are the most important measures of central tendency. the mean of a data set is its arithmetic average. the median of a data set is the middle value in its ordered list. the mode of a data set is its most frequently occurring value.