Consider the probability distribution below. x f(x) 20 0.05 30 0.35 40 0.45 50 0.15 The expected value is 37. Find the variance of x. Choices: 7.81 18.5     61 342.25

The probability distribution given describes the number of thunderstorms that a certain town may experience during the month of August. Let X represent the number of thunderstorms in August. Calculate the variance (VX). X=# of storms 0 1 2 3 p(x) 0.1 0.2 0.4 0.3 A.   1.06 B.    1.6 C.     0.94 D.     0.89

Save Use the probability distribution to complete parts (a) and (b) below. The number of defects per 1000 machine parts inspected Defects Probability 0.262 0.301 0.243 0.138 0.042 0.014 (a) Find the mean, variance, and standard deviation of the probability distribution. The mean is 1.4. (Round to one decimal place as needed.) The variance is 1.5. (Round to one decimal place as needed.) The standard deviation is 1.2. (Round to one decimal place as needed.) (b) Interpret the results. The mean is , so the average batch of 1000 machine parts has The standard deviation is so the typical number of defects in a batch of 1000 (Round to one decimal place as needed.) no defects. 1 or 2 defects. at least 2 defects. Clear all Check answe!

The probability distribution below is for the random variable X = the number of credits taken by a randomly selected first-year student at a large state university. Credits 14 15 16 17 Probability 0.05 0.65 0.20 0. 10 Show that the probability distribution of X is valid.