/*! 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 1 For each of the following situat... [FREE SOLUTION] | 91Ó°ÊÓ

91Ó°ÊÓ

For each of the following situations, state whether the parameter of interest is a mean or a proportion. It may be helpful to examine whether individual responses are numerical or categorical. (a) In a survey, one hundred college students are asked how many hours per week they spend on the Internet. (b) In a survey, one hundred college students are asked: "What percentage of the time you spend on the Internet is part of your course work?" (c) In a survey, one hundred college students are asked whether or not they cited information from Wikipedia in their papers. (d) In a survey, one hundred college students are asked what percentage of their total weekly spending is on alcoholic beverages. (e) In a sample of one hundred recent college graduates, it is found that 85 percent expect to get a job within one year of their graduation date.

Short Answer

Expert verified
(a) Mean, (b) Mean, (c) Proportion, (d) Mean, (e) Proportion.

Step by step solution

01

Understand the Question

The first step is to determine if the parameter of interest in each situation is a mean or a proportion. To do this, we need to identify whether the data collected is numerical (which generally leads to a mean) or categorical (which generally leads to a proportion).
02

Analyze Situation (a)

Situation (a) asks students how many hours per week they spend on the Internet. Since the response is numerical (hours), the parameter of interest is a mean.
03

Analyze Situation (b)

Situation (b) asks students what percentage of the time spent on the Internet is for course work. Although percentages might seem categorical, here the percentage of time is actually numerical, thus the parameter of interest is a mean.
04

Analyze Situation (c)

Situation (c) asks whether students cited information from Wikipedia in their papers, which has a yes/no response. This is categorical data, so the parameter of interest is a proportion.
05

Analyze Situation (d)

Situation (d) asks students what percentage of their total weekly spending is on alcoholic beverages. Like situation (b), even though it's a percentage, it's seen as a numerical response. Thus, the parameter of interest is a mean.
06

Analyze Situation (e)

Situation (e) provides the percentage of graduates who expect to get a job within one year. Since it directly gives a percentage of a population (expecting a job or not), this is categorical, hence the parameter is a proportion.

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.

Mean vs Proportion
When trying to determine if a parameter is a mean or a proportion, it's important to understand the nature of the data. These parameters help us summarize data in a meaningful way.

- **Mean**: Used for numerical data, represents the average. It requires adding up all data points and then dividing by the number of points. For example, calculating the average time students spend on the internet requires this approach. - **Proportion**: Used for categorical data, represents a part of a whole, often expressed as a percentage or fraction. When you're interested in finding out how many people out of a group have a particular characteristic, you measure the proportion.

Even though percentages sometimes seem categorical, they can still represent numerical data when collected as a part of a broader numerical context. Thus, clarify the nature of data before determining the parameter.
Numerical Data
Numerical data consists of numbers and allows for quantitative analysis. This is where we calculate measures such as averages or means. When students are asked about the number of hours spent on the internet, this requires numerical data.

- **Examples**: Hours spent online, percentage of time on coursework, and percentage of spending. These can all be quantified and used to find a mean.

Numerical data can be either continuous or discrete. - **Continuous**: Can take any value within a range (e.g., time, height). - **Discrete**: Consists of distinct values (e.g., number of calls, grade levels). Understanding and identifying numerical data correctly ensures accurate calculation of mean values.
Categorical Data
Categorical data revolves around qualities, categories, or labels rather than numbers. This type of data often focuses on frequency counts, which seek to identify proportions rather than means.

- **Examples**: Yes/No answers as in whether students cited Wikipedia, or the proportion of students expecting jobs after graduation.

Categorical data can be nominal or ordinal: - **Nominal**: Categories with no inherent order (e.g., gender, type of car). - **Ordinal**: Categories that do have a specific order (e.g., satisfaction ratings, age groups).
When working with categorical data, we often rely on percentages to understand the distribution or prominence of the responses received.
Survey Analysis
Survey analysis involves interpreting data collected from survey respondents. By understanding and categorizing data, surveys can reveal insightful conclusions about a group.

Surveys can yield both numerical and categorical data, thus a clear distinction between these types amplifies accuracy: - **Step 1**: Define your question. Know what you're measuring. - **Step 2**: Collect data properly. Ensure your questions extract either precise quantitative (numerical data) or categorical responses. - **Step 3**: Analyze by determining if a mean (for numerical) or proportion (for categorical) is the appropriate measure.
Survey analysis is an essential tool in research as it provides both averages and proportions, helping us better comprehend the gist of collected data.

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

Of all freshman at a large college, \(16 \%\) made the dean's list in the current year. As part of a class project, students randomly sample 40 students and check if those students made the list. They repeat this 1,000 times and build a distribution of sample proportions. (a) What is this distribution called? (b) Would you expect the shape of this distribution to be symmetric, right skewed, or left skewed? Explain your reasoning. (c) Calculate the variability of this distribution. (d) What is the formal name of the value you computed in (c)? (e) Suppose the students decide to sample again, this time collecting 90 students per sample, and they again collect 1,000 samples. They build a new distribution of sample proportions. How will the variability of this new distribution compare to the variability of the distribution when each sample contained 40 observations?

It is believed that nearsightedness affects about \(8 \%\) of all children. In a random sample of 194 children, 21 are nearsighted. Conduct a hypothesis test for the following question: do these data provide evidence that the \(8 \%\) value is inaccurate?

As part of a quality control process for computer chips, an engineer at a factory randomly samples 212 chips during a week of production to test the current rate of chips with severe defects. She finds that 27 of the chips are defective. (a) What population is under consideration in the data set? (b) What parameter is being estimated? (c) What is the point estimate for the parameter? (d) What is the name of the statistic can we use to measure the uncertainty of the point estimate? (e) Compute the value from part (d) for this context. (f) The historical rate of defects is \(10 \%\). Should the engineer be surprised by the observed rate of defects during the current week? (g) Suppose the true population value was found to be \(10 \%\). If we use this proportion to recompute the value in part (e) using \(p=0.1\) instead of \(\hat{p},\) does the resulting value change much?

A food safety inspector is called upon to investigate a restaurant with a few customer reports of poor sanitation practices. The food safety inspector uses a hypothesis testing framework to evaluate whether regulations are not being met. If he decides the restaurant is in gross violation, its license to serve food will be revoked. (a) Write the hypotheses in words. (b) What is a Type 1 Error in this context? (c) What is a Type 2 Error in this context? (d) Which error is more problematic for the restaurant owner? Why? (e) Which error is more problematic for the diners? Why? (f) As a diner, would you prefer that the food safety inspector requires strong evidence or very strong evidence of health concerns before revoking a restaurant's license? Explain your reasoning.

The General Social Survey asked the question: "After an average work day, about how many hours do you have to relax or pursue activities that you enjoy?" to a random sample of 1,155 Americans. \(^{26}\) A \(95 \%\) confidence interval for the mean number of hours spent relaxing or pursuing activities they enjoy was (1.38,1.92) (a) Interpret this interval in context of the data. (b) Suppose another set of researchers reported a confidence interval with a larger margin of error based on the same sample of 1,155 Americans. How does their confidence level compare to the confidence level of the interval stated above? (c) Suppose next year a new survey asking the same question is conducted, and this time the sample size is 2,500 . Assuming that the population characteristics, with respect to how much time people spend relaxing after work, have not changed much within a year. How will the margin of error of the \(95 \%\) confidence interval constructed based on data from the new survey compare to the margin of error of the interval stated above?

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.