/*! 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 50. In a congressional district, 55%... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 7: Q 50. (page 464)

In a congressional district, 55% of the registered voters are Democrats. Which of the following is equivalent to the probability of getting less than 50% Democrats in a random sample of size 100?

a. P(z<0.50鈭�0.55100)

b. P(z<0.50鈭�0.550.55(0.45)100)

c. P(z<0.55鈭�0.500.55(0.45)100)

d. P(z<0.50鈭�0.55100(0.55)(0.45))

e. P(z<0.55鈭�0.50100(0.55)(0.45))

Short Answer

Expert verified

The correct option is (b) pz<0.50鈭�0.550.55脳0.45100

Step by step solution

01

Given information

p=0.55p^=0.50n=100

02

Concept

蟽p^=p(1鈭�p)n

03

Calculation

渭p^=p=0.55蟽p^=p(1鈭�p)n=0.55(1鈭�0.55)100=0.55脳0.45100z=x鈭�渭蟽=0.50鈭�0.550.55脳0.45100

The sample proportion must be less than 50% with a probability of less than 50%

p(p^<50%)=pz<0.50鈭�0.550.55脳0.45100

Hence, the correct option is (b)

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 91影视!

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

Suppose that you have torn a tendon and are facing surgery to repair it. The orthopedic surgeon explains the risks to you. Infection occurs in 3%of such operations, the repair fails in 14%, and both infection and failure occur together 1%of the time. What is the probability that the operation is successful for someone who has an operation that is free from infection?

a. 0.8342

b. 0.8400

c. 0.8600

d. 0.8660

e. 0.9900

In a certain large population of adults, the distribution of IQ scores is strongly left skewed with a mean of 122 and a standard deviation of 5. Suppose 200 adults are randomly selected from this population for a market research study. For SRSs of size 200, the distribution of sample mean IQ score is

a. left-skewed with mean 122 and standard deviation 0.35.

b. exactly Normal with mean 122 and standard deviation 5.

c. exactly Normal with mean 122 and standard deviation 0.35.

d. approximately Normal with mean 122 and standard deviation 5.

e. approximately Normal with mean 122 and standard deviation 0.35.

Fillings How much do prices vary for filling a cavity? To find out, an insurance company randomly selects 10dental practices in California and asks for the cash (non-insurance) price for this procedure at each practice. The interquartile range is $74.

Dead battery? A car company claims that the lifetime of its batteries varies from car to car according to a Normal distribution with mean 渭=48months and standard deviation 蟽=8.2months. A consumer organization installs this type of battery in an SRS of 8 cars and calculates x炉=42.2months.

a. Find the probability that the sample mean lifetime is 42.2 months or less if the company's claim is true.

b. Based on your answer to part (a), is there convincing evidence that the company is overstating the average lifetime of its batteries?

The math department at a small school has 5teachers. The ages of these teachers are 23,34,37,42,58. Suppose you select a random sample of 4teachers and calculate the sample minimum age. Which of the following shows the sampling distribution of the sample minimum age?

a.

b.

c.

d.

e. None of these
See all solutions

Recommended explanations on Math Textbooks

Pure Maths

Read Explanation

Discrete Mathematics

Read Explanation

Statistics

Read Explanation

Mechanics Maths

Read Explanation

Decision Maths

Read Explanation

Geometry

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.