/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Q 5.110 A variable y of a finite populat... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

A variable y of a finite population has the following frequency distribution:

y1234
f22106

Suppose a member is selected at random from the population and let Y denote the value of the variable y for the member obtained.

a. Determine the probability distribution of the random variable Y.

b. Use random-variable notation to describe the events that Y takes on the value 3, a value less than 3, and a value of at least 3.

c. Find P(Y = 3), P(Y <3), and P(Y ≥ 3). Interpret your results.

d. Construct a probability histogram for the random variable Y.

Short Answer

Expert verified

Part a.

Random Variable (Y)

Probability

1

2/20 = 0.1

2

2/20 = 0.1

3

10/20 = 0.5

4

6/20 = 0.3

Part b.

On the value of 3: Y = 3

A value less than 3: Y < 3

A value of at least 3 : Y≥ 3

Part c.

P(Y=3) = 0.5

P(Y < 3) = 0.1 + 0.1 = 0.2

P(Y ≥ 3) = 0.5 + 0.3 = 0.8

Part d.

Step by step solution

01

Part (a) Step 1. Given information

The frequency distribution of a variable x in a finite population is as follows: :

y

1

2

3

4

f

2

2

10

6

Assume a member is chosen at random from the population, and Y is the value of the variable y for that member.

02

Part (a) Step 2. Formula Used 

The experiment is conducted out assuming that the random variable (X=x) occurs n times out of a total of N times. As a result of the f/N rule:

P (X=x) = n/N

03

Part (a) Step 3. Solution

Here, N = 2+2+10+6 = 20. As a result, the probability of random variable Y is as follows:

Random Variable

Probability

1

2/20 = 0.1

2

2/20 = 0.1

3

10/20 = 0.5

4

6/20 = 0.3

04

Part (b) Step 1. Solution 

Event where Y takes the value 3, can also be written as:

Y = 3

Event where Y takes a value less than 3, can also be written as :

Y < 3

Event where Y takes a value of at least 3, can also be written as :

Y ≥ 3

05

Part (c) Step 1. Solution

From the table,

P(Y = 3) = 0.5

P(Y < 3) = 0.1 + 0.1 = 0.2

P(Y ≥ 3 ) = 0.5 + 0.3 = 0.8

06

Part (d) Step 1. Solution

The probability histogram for the random variable Y is as follows:

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.

Over 30 million students worldwide already upgrade their learning with 91Ó°ÊÓ!

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

Jurors. From 10 men and 8 women in a pool of potential jurors 12 are chosen at random to constitute a jury. Suppose that you observe the number of men who are chosen for the jury. Let A be the event that at least half of the 12 jurors are men, and let B be the event that at least half of the 8 women are on the jury.

Part (a) Determine the sample space for this experiment

Part (b) Find (A or B) ,(A & B) and (A &(not B)), listing all the outcomes for each of those three events

Part (c) Are events A and B are mutually exclusive.? are events A and (not B)? are events (not A) and (not B)? Explain.

Fill in the blanks.

(a) A is a quantitative variable whose value depends on chance.

(b) A discrete random variable is a random variable whose possible values .

Mean as center of Gravity. Let X be a discrete random variable with a finite number of number of possible values say x1,x2.....xmFor convenience, set PK=P(X=xk),for K = 1, 2.....m . Think of a horizontal axis as a seesaw and each PKas a mass placed at point xkon the seesaw. The center of gravity of those masses is defined to be the point c on the horizontal axis at which a fulcrum could be placed to balance the seesaw.

Relative to the center of gravity , The torque acting on the seesaw by the mass PKis proportional to the product of that mass with the signed distance of the point XkFrom c That is , to ((xk-c). Pkshow that the center of gravity equal the mean of the random variable X ( hint: To balance, the total torque acting on the seesaw must be 0)

What is the difference between selecting a member at random from a finite population and taking a simple random sample of size 1?

Suppose that a simple random sample is taken from a finite population in which each member is classified as either having or not having a specified attribute. Fill in the following blanks.

(a) If sampling is with replacement, the probability distribution of the number of members sampled that have the specified attribute is a distribution.

(b) If sampling is without replacement, the probability distribution of the number of members sampled that have the specified attribute is a distribution.

(c) If sampling is without replacement and the sample size does not exceed % of the population size, the probability distribution of the number of members sampled that have the specified attribute can be approximated by a distribution.

See all solutions

Recommended explanations on Math Textbooks

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.