Math 133: 6.1 Worksheet #3 Coursepack, p. 361 Name: 6.1 WS #3: Discrete Random Variables and Expected Value case. 1. Determine whether the table represents a valid probability distribution and explain in each X P(X) 1 0.42 X P(X) X P(X) 55 -0.3 UI N 0.18 -8 0.2 0.34 65 0.8 -13 0.2 7 0.06 75 0.4 -15 0.2 P (x) $1 85 0.2 -18 0.2 Notvalid Not valid not equal to 2. The number of customers in line at a supermarket express checkout counter is a random variable with the following probability distribution 0.35- a. Explain why this 0.3 probability 0.3 distribution is 0.25 0.25 "discrete". Be 0.2 0.2 specific. Probability 0.15 Yes, it is discrete 0. 1 0.1 0.05 distribution .os. 2 3 5 Number of Customers in Line b. Find the probability that more than 3 customers are waiting in line = O. 5 c. Find P( X> 2) = 0.35 d. Compute the mean of the distribution: Hx= _ (1 decimal place) e. Compute the standard deviation of the distribution: ox= \ (1 decimal place) f. Interpret the mean and standard deviation in the context of the situation