/*! 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} Problem 36 Tomatoes The weights of four ran... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Tomatoes The weights of four randomly and independently selected bags of tomatoes labeled 5 pounds were found to be \(5.1\), \(5.0,5.3\), and \(5.1\) pounds. Assume Normality. a. Find a \(95 \%\) confidence interval for the mean weight of all bags of tomatoes. b. Does the interval capture \(5.0\) pounds? Is there enough evidence to reject a mean weight of \(5.0\) pounds?

Short Answer

Expert verified
The 95% confidence interval for the mean weight of all bags of tomatoes is determined by using the earlier computed values of mean, standard error and the Z-value. The determination of whether this interval captures 5.0 pounds will be based on whether 5.0 is contained within this confidence interval.

Step by step solution

01

Determine the mean of given weights

Add the 4 given weights and divide by 4 to calculate the mean. Mean \( \mu = \frac{5.1 + 5.0 + 5.3 + 5.1}{4} \)
02

Determine the standard deviation (SD)

First, find the differences between each given weight and the mean weight, square these differences, add them together and divide by 4-1=3 (because we apply Bessel's correction for sample SD). Take a square root of the result to find the standard deviation. SD \( = \sqrt{\frac{(5.1-\mu)^2 + (5.0-\mu)^2 + (5.3-\mu)^2 + (5.1-\mu)^2}{3}} \)
03

Determine the standard error (SE)

SE = SD/ \(\sqrt{n}\), where n = the number of bags of tomatoes = 4.
04

Calculate the 95% confidence interval for the mean weight

Using the formula for a 95% confidence interval for the mean, we find the interval by using \(\mu \pm Z(SE)\) , where Z is the Z-statistic for the 95% confidence level = 1.96. This provides upper and lower limits for the mean weight with a 95% confidence interval.
05

Verify if the interval contains 5.0 pounds

Check if 5.0 is between the confidence limits found in step 4.

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

Oranges A statistics instructor randomly selected four bags of oranges, each bag labeled 10 pounds, and weighed the bags. They weighed \(10.2,10.5,10.3\), and \(10.3\) pounds. Assume that the distribution of weights is Normal. Find a \(95 \%\) confidence interval for the mean weight of all bags of oranges. Use technology for your calculations. a. Decide whether each of the following three statements is a correctly worded interpretation of the confidence interval, and fill in the blanks for the correct option(s). i. I am \(95 \%\) confident that the population mean is between ii. There is a \(95 \%\) chance that all intervals will be between iii. I am \(95 \%\) confident that the sample mean is between b. Does the interval capture 10 pounds? Is there enough evidence to reject the null hypothesis that the population mean weight is 10 pounds? Explain your answer.

Pulse Difference The following numbers are the differences in pulse rate (beats per minute) before and after running for 12 randomly selected people. $$ 24,12,14,12,16,10,0,4,13,42,4, \text { and } 16 $$ Positive numbers mean the pulse rate went up. Test the hypothesis that the mean difference in pulse rate was more than 0 , using a significance level of \(0.05\). Assume the population distribution is Normal.

Exam Scores The distribution of the scores on a certain exam is \(N(70,10)\), which means that the exam scores are Normally distributed with a mean of 70 and standard deviation of \(10 .\) a, Sketch the curve and label, on the \(x\) -axis, the position of the mean, the mean plus or minus one standard deviation, the mean plus or minus two standard deviations, and the mean plus or minus three standard deviations. b. Find the probability that a randomly selected score will be between 50 and 90 . Shade the region under the Normal curve whose area corresponds to this probability.

Hamburgers (Example 9) A hamburger chain sells large hamburgers. When we take a sample of 30 hamburgers and weigh them, we find that the mean is \(0.51\) pounds and the standard deviation is \(0.2\) pound. a. State how you would fill in the numbers below to do the calculation. with Minitab. b. Report the confidence interval in a carefully worded sentence. Normal.

Four-year Graduation Rate (Example 6) A random sample of 10 colleges from Kiplinger's 100 Best Values in Public Education was taken. The mean rate of graduation within four years was \(43.5 \%\) with a margin of error of \(6.0 \%\). The distribution of graduation rates is Normal. (Source: http://portal.kiplinger.com/tool/ college/T014-S001-kiplinger-s-best-values- in-public-colleges/index php#colleges. Accessed via StatCrunch. Owner: Webster West.) a. Decide whether each of the following statements is worded correctly for the confidence interval, and fill in the blanks for the correctly worded one(s). i. We are \(95 \%\) confident that the sample mean is between \(\%\) and \(\%\). ii. We are \(95 \%\) confident that the population mean is between \(-\%\) and \(\%\). iii. There is a \(95 \%\) probability that the population mean is between \(\%\) and \(\% .\) b. Can we reject a population mean percentage of \(50 \%\) on the basis of these numbers? Explain.

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.