1. True or False. Justify for full credit. (a) If A and B STAT 200 | Page 5

( a) The steering committee of UMUC Green Solutions Team consists of 3 committee members. 10 people are interested in serving in the committee. How many different ways can the committee be selected?
( b) A bike courier needs to make deliveries at 6 different locations. How many different routes can he take?
9​. Let random variable ​x represent the number of girls in a family of three children.
( a) Construct a table describing the probability distribution.
( b) Determine the mean and standard deviation of ​x.( Round the answer to two decimal places)
10. ​Mimi just started her tennis class three weeks ago. On average, she is able to return 20 % of her opponent’ s serves. Assume her opponent serves 10 times.
( a) Let X be the number of returns that Mimi gets. As we know, the distribution of X is a binomial probability distribution. What is the number of trials( n), probability of successes( p) and probability of failures( q), respectively?
( b) Find the probability that that she returns at least 1 of the 10 serves from her opponent
11. ​A research concludes that the number of hours of exercise per week for adults is normally distributed with a mean of 4 hours and a standard deviation of 3 hours. ​Show all work. Just the answer, without supporting work, will receive no credit.
( a) Find the 75th percentile for the distribution of exercise time per week.( round the answer to 2 decimal places)
( b) What is the probability that a randomly selected adult has more than 7 hours of exercise per week?( round the answer to 4 decimal places)