## Elementary Statistics: A Step-by-Step Approach with Formula Card 9th Edition

Published by McGraw-Hill Education

# Chapter 5 - Discrete Probability Distributions - 5-2 Mean, Variance, Standard Deviation, and Expectation - Exercises 5-2 - Page 272: 4

#### Answer

Mean = μ = ∑X * P(X) = (5*0.05)+(6*0.2)+(7*0.4)+(8*0.1)+(9*0.15)+(10*0.1) = 7.4 Variance = $σ ^{2}$ = ∑[$X ^{2}$ * P(X)] - $μ ^{2}$ =[ $5 ^{2}$ *0.05 +$6 ^{2}$ * 0.2 + $7 ^{2}$ * 0.4 + $8 ^{2}$ *0.1 + $9 ^{2}$ *0.15 + $10 ^{2}$ *0.1 ] -$7.4 ^{2}$ =56.6-54.76 =1.84 Standard Deviation = σ = $\sqrt σ ^{2}$ = $\sqrt 1.84$ = 1.3565

#### Work Step by Step

--

After you claim an answer you’ll have 24 hours to send in a draft. An editor will review the submission and either publish your submission or provide feedback.