/*! 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. R8.1 It鈥檚 critical Find the appropr... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 8: Q. R8.1 (page 547)

It鈥檚 critical Find the appropriate critical value for constructing a confidence interval in each of the following settings.

a. Estimating a population proportion p at a 94% confidence level based on an SRS of size 125

b. Estimating a population mean 渭 at a 99% confidence level based on an SRS of size 58

Short Answer

Expert verified

Part a) The critical value is1.88

Part b) The critical value is2.665

Step by step solution

01

Part a) Step 1: Given information

Confidence level=94%

Sample size (n)=125

02

Part a) Step 2: Calculation

Level of significance(伪)=1-0.94=0.06

Using the standard normal, the critical value is set at6%

level of significance can be calculated as:

z伪2=z0.062=1.88

Therefore, the critical value is1.88

03

Part b) Step 1: Given information

Confidence level=99%

Sample size (n)=58

04

Part b) Step 2: Calculation

Level of significance (伪)=1-0.99=0.01

When the sample standard deviation is known, the t-critical value must be calculated.

The degree of freedom can be calculated as:

df=n-1=58-1=57

The critical value at the 1%level of significance is calculated as follows:

t伪2,df=t0.012,57=2.665

Therefore, the critical value is2.665

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

A 90%confidence interval for the mean 渭 of a population is computed from a random sample and is found to be90卤30. Which of the following could be the 95%confidence interval based on the same data?

a. 90卤21

b. 90卤30

c. 90卤39

d. 90卤70

e. Without knowing the sample size, any of the above answers could be the 95%confidence interval.

Price cuts (4.2) Stores advertise price reductions to attract customers. What type of price
cut is most attractive? Experiments with more than one factor allow insight into
interactions between the factors. A study of the attractiveness of advertised price discounts
had two factors: percent of all foods on sale (25%, 50%, 75%, or 100%) and whether the discount was stated precisely (e.g., as in 鈥�60% off鈥�) or as a range (as in 鈥�40% to 70% off鈥�). Subjects rated the attractiveness of the sale on a scale of 1 to 7.
a. List the treatments for this experiment, assuming researchers will use all combinations of the two factors.
b. Describe how you would randomly assign 200 volunteer subjects to treatments.
c. Explain the purpose of the random assignment in part (b).
d. The figure shows the mean ratings for the eight treatments formed from the two factors.35 Based on these results, write a careful description of how percent on sale and precise discount versus range of discounts influence the attractiveness of a sale.

A quality control inspector will measure the salt content (in milligrams) in a random

sample of bags of potato chips from an hour of production. Which of the following would result in the smallest margin of error in estimating the mean salt content 渭?

a. 90%confidence; n=25

b. 90%confidence; n=50

c. 95%confidence; n=25

d. 95%confidence; n=50

e. n = 100 at any confidence level

One reason for using a t distribution instead of the standard Normal distribution to find critical values when calculating a level C confidence interval for a population mean is that

a. zcan be used only for large samples.

b. zrequires that you know the population standard deviation 蟽.

c. z requires that you can regard your data as an SRS from the population.

d. z requires that the sample size is less than 10% of the population size.

e. a z critical value will lead to a wider interval than a t critical value.

Whelks and mussels The small round holes you often see in seashells were drilled by other sea creatures, who ate the former dwellers of the shells. Whelks often drill into mussels, but this behavior appears to be more or less common in different locations. Researchers collected whelk eggs from the coast of Oregon, raised the whelks in the laboratory, then put each whelk in a container with some delicious mussels. Only9 of 98 whelks drilled into a mussel.
See all solutions

Recommended explanations on Math Textbooks

Discrete Mathematics

Read Explanation

Statistics

Read Explanation

Mechanics Maths

Read Explanation

Decision Maths

Read Explanation

Logic and Functions

Read Explanation

Applied Mathematics

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.