Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 6: Q. 6.3 (page 436)

Let D be the difference in the number of puzzles solved by two randomly selected subjects in a 5-minute period. What is the standard deviation of D?

a. 0

b. 0.81

c. 0.9

d. 1.27

e. 1.8

Short Answer

Expert verified

(c) The standard deviation of D is 0.9

Step by step solution

01

Given Information

Consider that the following is the probability distribution:

X1234
PX
0.200.400.300.10
02

Step 2  / 3Step 2: Calculations

D's standard deviation can be calculated as follows:

Ex=∑xpx=10.2+20.4+30.3+40.1=0.2+0.8+0.9+0.4=2.3VX=EX−EX2=EX−2.32=∑X−2.32px=1−2.32p1+2−2.32p2+3−2.32p3+4−2.32p4=0.338+0.036+0.147+0.289=0.81SD=VX=0.81=0.9

03

Explanation for options

a. The standard deviation will not be 0

b. The standard deviation will not be 0.81

c. The standard deviation will be 0.9

d. The standard deviation will not be 1.27

e. The standard deviation will not be 1.8

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

.Life insurance The risk of insuring one person’s life is reduced if we insure many people. Suppose that we insure two 21-year-old males, and that their ages at death are independent. If X1andX2are the insurer’s income from the two insurance policies, the insurer’s average income W on the two policies is

W=X1+X22=0.5X1+0.5X2

Find the mean and standard deviation of W. (You see that the mean income is the same as for a single policy but the standard deviation is less.)

Get on the boat! Refer to Exercise 3. Find the mean of Y. Interpret this value.

Ms. Hall gave her class a 10-question multiple-choice quiz.

LetX=the number of questions that a randomly selected student in the class answered correctly. The computer output gives information about the probability distribution of X. To determine each student’s grade on the quiz (out of 100), Ms. Hall will multiply his or her number of correct answers by 5and then add 50. Let G=the grade of a randomly chosen student in the class.

More easy quiz

a. Find the mean of G.

b. Find the range of G.

If Jeff gets 4 game pieces, what is the probability that he wins exactly 1 prize?

a. 0.25

b. 1.00

c. (41)(0.25)3(0.75)341(0.25)3(0.75)3

d. (41)(0.25)1(0.75)341(0.25)1(0.75)3

e.(0.75)3(0.75)1

Quick, click! An Internet reaction time test asks subjects to click their mouse button as soon as a light flashes on the screen. The light is programmed to go on at a randomly selected time after the subject clicks “Start.” The density curve models the amount of time Y (in seconds) that the subject has to wait for the light to flash.

a) Find and interpret P(Y>3.75)

b) What is μY? Explain your answer.

c) Find the value of k that makes this statement true:P(Y≤k)=0.38
See all solutions

Recommended explanations on Math Textbooks

Logic and Functions

Read Explanation

Probability and Statistics

Read Explanation

Discrete Mathematics

Read Explanation

Geometry

Read Explanation

Calculus

Read Explanation

Statistics

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free