Question

A scientist was interested in studying if students political beliefs change as they go through college. Two hundred randomly selected students were asked before they entered college if they would consider themselves liberal or conservative. Four years later, the same two hundred students were asked if they would consider themselves, liberal or conservative. The scientist decided to perform McNemar's test. The data is below. What is the null hypothesis? After College Before College Liberal Conservative Liberal 80 15 Conservative 20 85

A. -0.85 or 0.85

B. -0.39 or 0.39

C. -9.75 or -9.75

D. 1.96 or -1.96

Answer 1

You’re answer would be B love!

Answer 2

The null hypothesis in this considered experiment is: There is no change in their political beliefs as they go through college.

How to form the hypotheses?

There are two hypotheses. First one is called null hypothesis and it is chosen such that it predicts nullity or no change in a thing. It is usually the hypothesis against which we do the test. The hypothesis which we put against null hypothesis is alternate hypothesis.

Null hypothesis is the one which researchers try to disprove.

Here, it is specified that the scientist wants to study if students political beliefs change as they go through college. He wants to test if there are changes in the proportions of people who are liberal( or conservative).

Given that:

100 students before and after were asked their policial belief, as shown in table:

                               Liberal                Conservative

After college              80                       20

Before college           85                       15

Proportion of liberal = 1 - proportion of conservatives

So we will symbolize the hypotheses in terms of one of them, let it be proportions of liberals.

Sample size = 100

Favorable cases = Number of people from sample who consider themselves liberal. = X (say)

• After college:

Sample proportion is: $\hat{p}_1 = \dfrac{X}{N} = \dfrac{80}{100} = 0.8$

• Before college:

Sample proportion is: $\hat{p}_2 = \dfrac{X}{N} = \dfrac{85}{100} = 0.85$

Let p1 and p2 be the population proportion of people believing themself liberal after and before college respectively.

Then, the null hypothesis will assume that the claim of difference in belief the scientist wants to test is false, and therfore,

$H_0: p_1 = p_2$ or $H_0: p_1 - p_2 = 0$ (no difference, proportions are same, indicating that belief of students doesn't change much, as d)

Thus, the null hypothesis in this considered experiment is: There is no change in their political beliefs as they go through college.

Learn more about null and alternative hypothesis here:

https://brainly.com/question/18831983