Chapter 26, Problem 36E

a)

To determine

To make a sensible change and find the expected count which will be acceptable.

Answer to Problem 36E

The condition for chi-square test is satisfied.

Explanation of Solution

Given:

  

Formula:

  $E=\frac{Rowtotal\times Columntotal}{Total}$

The expected counts of Violent and Other category is too small. Therefore, combine that both cells and will try to find expected counts again.

Using excel,

  

The expected counts are greater than 5. Therefore, condition for chi-square test is satisfied. Hence, it is appropriate to use Chi-square test of Homogeneity.

b)

To determine

To perform chi-square test.

Answer to Problem 36E

There is not sufficient evidence to support the claim that the types of crime are different during the moon.

Explanation of Solution

Given:

  

The null and alternative hypotheses:

  $H_0$ : The type of illegal activity is the same on the full moon as not on the full moon.

  $H_a$ : The type of illegal activity is different on the full moon.

Using excel,

  

  ${\chi }^2$ = 2.30 and P-value = 0.5118

Decision: The p-value > 0.05, fail to reject H0.

Conclusion: There is not sufficient evidence to support the claim that the types of crime are different during the moon.