Question

Three tables listed below show random variables and their probabilities. However, only one of these is actually a probability distribution. A B C x P(x) x P(x) x P(x) 25 0.2 25 0.2 25 0.2 50 0.4 50 0.4 50 0.4 75 0.1 75 0.1 75 0.1 100 0.3 100 0.5 100 0.7 a. Which of the above tables is a probability distribution? b. Using the correct probability distribution, find the probability that x is: (Round the final answers to 1 decimal place.) 1. Exactly 75 = 2. No more than 50 = 3. More than 25 = c. Compute the mean, variance, and standard deviation of this distribution. (Round the final answers to 2 decimal places.) 1. Mean µ 2. Variance σ2 3. Standard deviation σ

Answer 1

Griven that 25 50 loo . "Total Px) o2 04 0-1 0.3 a) EPCXi)- 0.2+0.9 +0 } +0.3 It is probability dism bution. Mean-E(X)-2x PCX) E (x)- 62.s

2 E(X'.): 4625 2 462S- (62.S Tez 18-351 7/8.75 SD 26.8