In the article "Growing Pains and Fear of Gangs", 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.

At the \(1%\) significance level, do the data provide sufficient evidence to conclude that an association exists between worry about a gang attack and actually being a victim of a gang attack?

Short Answer

Expert verified

The data provide is sufficient evidence to conclude that worry about gang attack and actually being a victim of a gang attack.

Step by step solution

01

Step 1. Given information

The level of significance \(\alpha =0.01\)

02

Step 2. Calculation

Consider the below test hypothesis.

Null hypothesis:

\(H_{0}\): There is no association between worry about gang attack and actually being a victim of a gang attack

Alternative hypothesis:

\(H_{a}\): There is association between worry about gang attack and actually being a victim of a gang attack.

By using any software perform the chi-square homogeneity test to find the test statistic.

Enter the given data,

Then we get, the chi-square static as \(=23.455, p-value=0.00\)

Then, we have the

the rejection rule:

\(p-value \leq \alpha\), then null hypothesis rejected.

The level of significance \(\alpha =0.01\)

Here , clearly \(p-\)value is less than the level of significance.

\(p-value (0.00)<\alpha (0.01)\)

So, the null hypothesis is rejected at \(1%\) significant level.

Thus the results are statistically significant at \(1%\) significant level.

Hence,

The data provide is sufficient evidence to conclude that worry about gang attack and actually being a victim of a gang attack.

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 Exercises 12.18-12.23, we have provided a distribution and the observed frequencies of the values of a variable from a simple random sample of a population. In each case, use the chi-square goodness-of-fit test to decide, at the specified significance level, whether the distribution of the variable differs from the given distribution.

Distribution: 0.2, 0.4, 0.3, 0.1

Observed frequencies: 85, 215, 130, 70

Significance level = 0.05

What is meant by saying that a variable has a chi-square distribution?

In each of the given Exercises, we have given the number of possible values for two variables of a population. For each exercise, determine the maximum number of expected frequencies that can be less than 5 in order that Assumption 2 of Procedure 12.2 on page 506 to be satisfied. Note: The number of cells for a contingency table with m rows and n columns is m⋅n.

12.71 two and three

In each of Exercises 12.24-12.33, apply the chi-square goodness-of-fit test, using either the critical-value approach or theP-value approach, to perform the required hypothesis test.
An American roulette wheel contains 18red numbers, 18black numbers, and 2green numbers. The following table shows the frequency with which the ball landed on each color in 200trials.

At the 5%significance level, do the data suggest that the wheel is out of balance?

To decide whether two variables of a population are associated, we usually need to resort to inferential methods such as the chi-square independence test. Why?

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