Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Consider a population consisting of the following five values, which represent the number of video rentals during the academic year for each of five housemates: \(\begin{array}{lll} 8 & 14&16 & 10 & 11\end{array}\) a. Compute the mean of this population. b. Select a random sample of size 2 by writing the numbers on slips of paper, mixing them, and then selecting \(2 .\) Compute the mean of your sample. c. Repeatedly select samples of size 2 , and compute the \(\bar{x}\) value for each sample until you have the results of 25 samples. d. Construct a density histogram using the \(25 \bar{x}\) values. Are most of the \(\bar{x}\) values near the population mean? Do the \(\bar{x}\) values differ a lot from sample to sample, or do they tend to be similar?

Short Answer

Expert verified
Due to the exercise set-up, no concrete numeric answer can be given. The result of this exercise is more about understanding the concept of population mean, sample mean, and how to interpret those values.

Step by step solution

01

Compute the population mean

The population consists of the number of video rentals: 8, 14, 16, 10, and 11. We calculate the mean by adding each number and then dividing by the total count. So, \(\(Mean = \frac{8 + 14 + 16 + 10 + 11}{5}\)
02

Compute the mean of a sample of size 2

You need to randomly select two numbers from the population and then calculate their mean. This process can give a different result each time it's executed depending on the numbers chosen.
03

Compute the means of 25 samples

You need to repeat the process in step 2, 25 times and calculate the mean for each sample.
04

Construct a density histogram

The density histogram can be constructed using the \(25 \bar{x}\) values. The histogram will provide a visual representation of the means from the 25 samples.
05

Analyze the results

The goal is to explore whether most sample means are close to the population mean, and whether there are significant differences in the sample means. This can be interpreted by looking at the histogram. If most of the sample means are close to the population mean, this suggests that the sample mean is a good estimator of the population mean. If the bar heights for different sample means don't vary much, it could suggest that sample means tend not to differ a lot.

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 Vaia!

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

Water permeability of concrete can be measured by letting water flow across the surface and determining the amount lost (in inches per hour). Suppose that the permeability index \(x\) for a randomly selected concrete specimen of a particular type is normally distributed with mean value 1000 and standard deviation 150 . a. How likely is it that a single randomly selected specimen will have a permeability index between 850 and \(1300 ?\) b. If the permeability index is to be determined for each specimen in a random sample of size 10 , how likely is it that the sample average permeability index will be between 950 and \(1100 ?\) between 850 and 1300 ?

Newsweek (November 23, 1992) reported that 40\% of all U.S. employees participate in "self-insurance" health plans \((\pi=.40)\). a. In a random sample of 100 employees, what is the approximate probability that at least half of those in the sample participate in such a plan? b. Suppose you were told that at least 60 of the \(100 \mathrm{em}\) ployees in a sample from your state participated in such a plan. Would you think \(\pi=.40\) for your state? Explain.

Let \(x\) denote the time (in minutes) that it takes a fifth-grade student to read a certain passage. Suppose that the mean value and standard deviation of \(x\) are \(\mu=2 \mathrm{~min}\) and \(\sigma=0.8\) min, respectively. a. If \(\bar{x}\) is the sample average time for a random sample of \(n=9\) students, where is the \(\bar{x}\) distribution centered, and how much does it spread out about the center (as described by its standard deviation)? b. Repeat Part (a) for a sample of size of \(n=20\) and again for a sample of size \(n=100\). How do the centers and spreads of the three \(\bar{x}\) distributions compare to one another? Which sample size would be most likely to result in an \(\bar{x}\) value close to \(\mu\), and why?

Suppose that a sample of size 100 is to be drawn from a population with standard deviation \(10 .\) a. What is the probability that the sample mean will be within 2 of the value of \(\mu\) ? b. For this example \((n=100, \sigma=10)\), complete each of the following statements by computing the appropriate value: i. Approximately 95% of the time, \(\bar{x}\) will be within _____ of \(\mu .\) ii. Approximately 0.3% of the time, \(\bar{x}\) will be farther than _____ from\(\mu .\)

In the library on a university campus, there is a sign in the elevator that indicates a limit of 16 persons. Furthermore, there is a weight limit of \(2500 \mathrm{lb}\). Assume that the average weight of students, faculty, and staff on campus is \(150 \mathrm{lb}\), that the standard deviation is \(27 \mathrm{lb}\), and that the distribution of weights of individuals on campus is approximately normal. If a random sample of 16 persons from the campus is to be taken: a. What is the expected value of the sample mean of their weights? b. What is the standard deviation of the sampling distribution of the sample mean weight? c. What average weights for a sample of 16 people will result in the total weight exceeding the weight limit of \(2500 \mathrm{lb} ?\) d. What is the chance that a random sample of 16 persons on the elevator will exceed the weight limit?

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.

Sign-up for free