Answered step by step
Verified Expert Solution
Link Copied!

Question

1 Approved Answer

A survey of 100 businesses revealed that the mean after-tax profit was $80,000 and the standard deviation was $15,000. Determine the 90% confidence interval estimate

A survey of 100 businesses revealed that the mean after-tax profit was $80,000 and the standard deviation was $15,000.

  1. Determine the 90% confidence interval estimate of the mean after-tax profit.


    a.

    [76904, 83096]


    b.

    [76130, 83870]


    c.

    [77540, 82460]


    d.

    [78032, 81968]


    e.

    [77060, 82940]

QUESTION 3

  1. It is desired to estimate the mean tensile strength for roof hangers.

    It is known that the standard deviation of measurements of tensile strength is 0.25. (Units are Newton per square meter.)

    As it is very important for safety, the 99% confidence interval needs to have a margin smaller than 0.05.

    What is the minimum required sample size?


    a.

    463


    b.

    85


    c.

    167


    d.

    116


    e.

    261

Step by Step Solution

3.39 Rating (158 Votes )

There are 3 Steps involved in it

Step: 1

1 Given Mean 80000 Standard deviation 15000 Sample size 100 Confidence level 90 Using the formula ... blur-text-image

Get Instant Access to Expert-Tailored Solutions

See step-by-step solutions with expert insights and AI powered tools for academic success

Step: 2

blur-text-image

Step: 3

blur-text-image

Ace Your Homework with AI

Get the answers you need in no time with our AI-driven, step-by-step assistance

Get Started

Recommended Textbook for

Applied Statistics In Business And Economics

Authors: David Doane, Lori Seward

4th Edition

73521485, 978-0073521480

More Books

Students also viewed these Economics questions

Question

Solve y" + y = 1 - t 2 / 2 ? if 0 Answered: 1 week ago

Answered: 1 week ago