91Ó°ÊÓ

Explaining confidence The admissions director for a university found that $(107.8,116.2)$is a $95\%$confidence interval for the mean IQ score of all freshmen. Discuss whether each of the following explanations is correct, based on that information.

a. There is a $95\%$probability that the interval from role="math" localid="1654200953396" $107.8\mathrm{to}116.2$contains $\mathrm{μ}$.

b. There is a $95\%$chance that the interval$(107.8,116.2)$contains $\stackrel{¯}{x}$.

c. This interval was constructed using a method that produces intervals that capture the true mean in $95\%$of all possible samples.

d. If we take many samples, about $95\%$of them will contain the interval $(107.8,116.2)$.

e. The probability that the interval $(107.8,116.2)$captures $\mathrm{μ}$ is either $0$ or $1$, but we don’t know which.

Step by step solution

01

Given Information

$95\%$ confidence interval for mean IQ is given as$(107.8,116.2)$

02

To determine whether there is a 95% probability for the interval from 107.8 to 116.2 contains μ

Confidence Interval may or may not contain mean $\mathrm{μ}$.

Probability will be either $0\mathrm{or}1$.

It cannot be $0.95$.

Explanation is incorrect.

03

To check if there is 95% chance for the interval (107.8,116.2) contains x¯

Sample mean is generally center of given confidence interval.

Probability is $1(\mathrm{not}0.95)$

Explanation is Incorrect.

04

To check is this interval was constructed using a method that produces intervals that capture the true mean in 95% of all possible samples.

True Mean is also called Population Mean.

Here, interval of $95\%$of possible samples contain population/true mean.

Hence, Explanation is correct.

05

To check  if about 95% of the samples taken will contain the interval (107.8,116.2)

If sample mean is samples is same, sample contains only same confidence interval. Sample mean in a lot is identical less than $95\%$of possible samples.

Explanation is Incorrect.

06

To check if the probability for the interval (107.8,116.2) captures μ is either 0 or 1 but it is unknown.

Population mean may or may not contain $\mathrm{μ}$.

Probability is $0\mathrm{or}1$.

Explanation is correct.

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!