/*! 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 60 Let \(X=\) GPA for students in y... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

Let \(X=\) GPA for students in your school. a. What would the sampling distribution of the sample mean look like if you sampled every student in the school, so the sample size equals the population size? (Hint: The sample mean then equals the population mean.) b. How does the sampling distribution compare to the population distribution if we take a sample of size \(n=1 ?\)

Short Answer

Expert verified
a. The sampling distribution would be a single point at the population mean. b. For \(n=1\), the sampling distribution is the same as the population distribution.

Step by step solution

01

Understanding the Sampling Distribution with Full Population

When you sample every student in the school, your sample size is equal to the population size. This means the sample mean is identical to the population mean. Consequently, the sampling distribution is not really distributed; it's a single value equal to the population mean, since there is no variability to account for.
02

Analysis for Sample Size of n=1

In a sample of size \(n=1\), each sample is just a single student's GPA, drawn randomly from the population. Therefore, the mean of such a sample is the GPA of that lone student. Over many such samples (each with \(n=1\)), the sampling distribution of the mean would be the same as the population distribution of GPAs, since every possible sample's mean (one student's GPA) is drawn directly from the population.

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!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Population Mean
To truly grasp the concept of population mean, let's explore its role in statistics. The population mean is the average value of a key measurement if you consider every individual in a given group or population. For example, if each student's GPA in a school is added together and then divided by the total number of students, the result is the population mean GPA.

Understanding the difference between sample mean and population mean is crucial. The sample mean is an average value derived from a subset of the population, while the population mean is the average across the entire population. The population mean is a vital benchmark as it represents the true average, unaffected by sampling variations.

When your sample size equals the population size, the sample mean becomes equal to the population mean, eliminating the sampling variability. This is essential when studying the sampling distribution of a sample mean.
Sample Size
Sample size refers to the number of observations or data points taken from a population to form a sample. It is a critical factor that influences the reliability and accuracy of statistical analyses.

In our exercise, when the sample size equals the population size, the sampling distribution of the sample mean becomes a single value: the population mean. But what happens if the sample size is just one?

With a sample size of 1, each sampled mean is simply the data point itself. The mean directly reflects the individual's observation, making it equivalent to the population distribution. Larger sample sizes tend to result in a more normal distribution of the sample mean, whereas smaller ones, like n=1, result in a distribution that mirrors the population distribution quite closely.
GPA
GPA, or Grade Point Average, is a standard metric used to evaluate a student's academic performance. It is usually calculated by assigning numerical values to letter grades.

In the context of this problem, each student's GPA can be considered as a single data point in the entire school's population. The average of all these GPAs would give you the population mean GPA.

In statistical terms, GPA serves as a random variable that can help understand the statistical concepts of sampling and population distribution. By assessing different GPAs among students, educational institutions and other stakeholders can analyze overall academic performance and make informed decisions.
Population Distribution
The population distribution represents how often each possible value of a variable occurs in an entire population. It shapes our expectations of the data's spread and central tendencies.

In many cases, assuming the population distribution is normal provides ease in analysis, though real-world data might display variations. In the school GPA context, each GPA is a data point in the population distribution.

If you take a very small sample size, like one student, the sampled means mimic the population distribution directly. Hence, for a sample size of 1, the sampling distribution of the mean reflects the actual population distribution, as it is based on the individual's GPA data without any aggregation or averaging effects.

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

Explain how the standard deviation of the sampling distribution of a sample proportion gives you useful information to help gauge how close a sample proportion falls to the unknown population proportion.

Based on data from the 2010 Major League Baseball season, \(X=\) number of home runs the San Francisco Giants hit in a game has a mean of 1.0 and a standard deviation of 1.0 . a. Do you think \(X\) has a normal distribution? Why or why not? b. Suppose that this year \(X\) has the same distribution. Report the shape, mean, and standard deviation of the sampling distribution of the mean number of home runs the team will hit in its 162 games. c. Based on the answer to part b, find the probability that the mean number of home runs per game in this coming season will exceed 1.50 .

An exam consists of 50 multiplechoice questions. Based on how much you studied, for any given question you think you have a probability of \(p=0.70\) of getting the correct answer. Consider the sampling distribution of the sample proportion of the 50 questions on which you get the correct answer. a. Find the mean and standard deviation of the sampling distribution of this proportion. b. What do you expect for the shape of the sampling distribution? Why? c. If truly \(p=0.70\), would it be very surprising if you got correct answers on only \(60 \%\) of the questions? Justify your answer by using the normal distribution to approximate the probability of a sample proportion of 0.60 or less.

At a university, \(60 \%\) of the 7,400 students are female. The student newspaper reports results of a survey of a random sample of 50 students about various topics involving alcohol abuse, such as participation in binge drinking. They report that their sample contained 26 females. a. Explain how you can set up a binary random variable \(X\) to represent gender. b. Identify the population distribution of gender at this university. Sketch a graph. c. Identify the data distribution of gender for this sample. Sketch a graph. d. Identify the sampling distribution of the sample proportion of females in the sample. State its mean and standard deviation for a random sample of size \(50 .\) Sketch a graph. e. Use the Sampling Distribution app accessible from the book's website to check your answers from parts b through d. Set the population proportion equal to \(p=0.60\) and \(n=50 .\) Compare the population, data, and sampling distribution graph from the app with your graphs from parts b through d.

According to data on StatCrunch.com, the mean number of \(X=\) pets owned per household in a certain area in the United States was 1.88 pets, and the standard deviation was 1.67 . a. Does \(X\) have a normal distribution? Explain. b. For a random sample of 100 houses, describe the sampling distribution of \(\bar{x}\) and give its mean and standard deviation. What is the effect of \(X\) not having a normal distribution?

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.