Name: Math 133: 6.1 Worksheet #3 6.1 WS #3: Discrete Random Variables and Expected Value 1. Determine whether the table represents a valid probability distribution and explain in each case. X P(X ) X P(X) X P(X) 1 0.42 55 -0.3 -8 0.2 0.18 65 0.8 -13 0.2 UI N 0.34 75 0.4 -15 0.2 7 0.06 85 0.2 18 0.2 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 0.3 probability distribution is 0.25 0.25 "discrete". Be 0.2 0.2 specific. Probability 0.15 0.1 0.1 0.1 0.05 0.05 3 5 Number of Customers in Line b. Find the probability that more than 3 customers are waiting in line = c. Find P(X>2) = 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. ve sAT