Are the observed frequencies variables? What about the expected frequencies? Explain your answers.

Short Answer

Expert verified

Yes. The observed frequencies are the frequencies which falls under the classification of characteristic variable. Observed frequencies are almost equal to the expected frequencies. So, each observed frequency is roughly equal to its corresponding expected frequency.

Step by step solution

01

Step 1. Given information

We need to explain whether the observed frequencies are variables and also need to give the definition for the expected frequencies.

02

Step 2. A brief explanation about the observed and the expected frequencies:

Yes. The observed frequencies are the frequencies which falls under the classification of characteristic variable. Observed frequencies are almost equal to the expected frequencies. So, each observed frequency is roughly equal to its corresponding expected frequency.

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

In each of the given Exercises, we have presented a contingency table that gives a cross-classification of a random sample of values for two variables, x, and y, of a population. For each exercise, perform the following tasks.

a. Find the expected frequencies. Note: You will first need to compute the row totals, column totals, and grand total.

b. Determine the value of the chi-square statistic.

c. Decide at the 5% significance level whether the data provide sufficient evidence to conclude that the two variables are associated.

Fear of Gangs. In the article "Growing Pains and Fear of Gangs" (Applied Psychology in Criminal Justice, Vol. 5, No. 2, pp. 139-164), B. Brown and W. Benedict examined the relationship between worry about a gang attack and actually being a victim of a gang attack. Interviews of a sample of high school students yielded the following contingency table.

A poll conducted by Gallup asked American adults about vegetarianism. This problem is based on that poll. Of independent random samples of 500men and 512women, 20of the men and 36of the women said they were vegetarians. At the 5%significance level do the data provide sufficient level do the data provide sufficient evidence to conclude that a difference exists in the proportions of male and female vegetarians?

Part (a): Use the two-portions z-test to perform the required hypothesis test.

Part (b): Use the chi-square homogeneity test to perform the required hypothesis test.

Part (c): Compare your results in parts (a) and (b).

Part (d): Explain what principle is being illustrated.

P.Noakes et al. researched the effects of fatty acids found in oily fish on lowering the risk of allergic disease in the article "Increased Intake of Oily Fish in Pregnancy: Effects on Neonatal Immune Responses and on Clinical Outcomes in Infants at 6Mo.". Pregnant women were randomly assigned to continue their habitual diet (control group), which was low in oily fish, or to consume two portions of salmon per week (treatment group). Their infants were clinically evaluated at 6months of age and the frequency of many different symptoms was recorded. Of the 37infants in the control group,12had symptoms of dry skin; and of the 45 infants in the experimental group, 14had symptoms of dry skin. At thedata-custom-editor="chemistry" 5%significance level, do the data provide sufficient evidence to conclude that a difference exists in the proportions of infants who have symptoms of dry skin at6 months between those whose mothers continue their habitual diet and those whose mothers consume two portions of salmon per week?

Part (a): Use the two-portionsz-test to perform the required hypothesis test.

Part (b): Use the chi-square homogeneity test to perform the required hypothesis test.

Part (c): Compare your results in parts (a) and (b).

Part (d): Explain what principle is being illustrated.

The Quinnipiac University Pol conducts nationwide surveys as a public service and for research. This problem is baed on the results of one such poll that asked independent random samples of American adults in urban, suburban, and rural regions, "Do you support or oppose requiring background checks for all gun buyers?" Here are the results.

At the 1%significance level, do the data provide sufficient evidence to conclude that a difference exists in the proportions of supporters among the three regions?

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