The random variable X is the crew size of a randomly selected shuttle mission. Its probability distribution is shown below. Complete parts a through c. 24 5 6 7 8 P(X=x) 0.036 0.032 0.315 0.153 0.456 0.008 X a. Find and interpret the mean of the random variable. u = 5.949 (Round to three decimal places as needed.) Interpret the mean. Select the correct choice below and fill in the answer box to complete your choice. (Round to three decimal places as needed.) A. The average number of persons in a shuttle crew is 5.949 person(s). B. The most common number of persons in a shuttle crew is person(s) b. Obtain the standard deviation of the random variable. (Round to three decimal places as needed.) =