A researcher predicts that watching a film on institutionalization will change students’ attitudes about chronically mentally ill patients. The researcher randomly selects a class of 36 students, shows them the film, and gives them a questionnaire about their attitudes. The mean score on the questionnaire for these 36 students is 70. The score for a similar class of students who did not see the film is 75. The standard deviation is 12. Using the five steps of hypothesis testing and the 5% significance level (alpha), does showing the film change students’ attitudes towards the chronically mentally ill?

Question

A researcher predicts that watching a film on institutionalization will change students’ attitudes about chronically mentally ill patients. The researcher randomly selects a class of 36 students, shows them the film, and gives them a questionnaire about their attitudes. The mean score on the questionnaire for these 36 students is 70. The score for a similar class of students who did not see the film is 75. The standard deviation is 12. Using the five steps of hypothesis testing and the 5% significance level (alpha), does showing the film change students’ attitudes towards the chronically mentally ill?

What is your null hypothesis? Alternate hypothesis?
Is this a one-tailed or two-tailed hypothesis?
What is your obtained z?
What is the critical value for z?
Do you reject or fail to reject the null hypothesis?
State in words what you have found.

Answer 1

Ho: Mean1 = mean2

Ha: Mean1 ≠ mean2

Z = (mean1 - mean2)/standard error (SE) of difference between means

SEdiff = √(SEmean1^2 + SEmean2^2)

SEm = SD/√n

If only one SD is provided, you can use just that to determine SEdiff.

Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion related to the Z score.

This should start you out.

Answer 2

waht is the null and alternate hypothesis of a researcher prdicts that watching a film institutionalization will change students attitudes about chronically mentally ill patients

Answer 3

To determine whether showing the film changes students' attitudes towards the chronically mentally ill, we can follow the five steps of hypothesis testing:

1. Formulate the null hypothesis (H0) and the alternate hypothesis (Ha):

Null hypothesis (H0): Watching the film does not change students' attitudes towards the chronically mentally ill.
Alternate hypothesis (Ha): Watching the film changes students' attitudes towards the chronically mentally ill.

2. Determine the type of hypothesis test:

Since the question asks whether the film changes attitudes and does not specify a direction, this is a two-tailed hypothesis test.

3. Set the significance level (α):

The significance level, also known as α, indicates the probability of rejecting the null hypothesis when it is true. In this case, the significance level is given as 5%, which means α = 0.05.

4. Calculate the obtained z-score:

The formula for calculating the z-score is:
z = (x̄ - μ) / (σ / √n)

Where:
x̄ = mean score of the sample (70 in this case)
μ = mean score of the population (75 for the class that did not see the film)
σ = standard deviation of the population (12)
n = sample size (36)

Substituting these values into the formula, we can calculate the obtained z-score:

z = (70 - 75) / (12 / √36) = -5 / 2 = -2.5

5. Determine the critical value:

Since this is a two-tailed hypothesis test with a significance level of 0.05, we need to divide α by 2 to get the critical values for the upper and lower tails. Looking up the z-scores in a standard normal distribution table, we find that the critical value for each tail is approximately ±1.96.

6. Compare the obtained z-score with the critical value:

Since |z| > |critical value| (|-2.5| > |1.96|), we reject the null hypothesis.

7. State the conclusion:

Based on the data, we can conclude that showing the film does change students' attitudes towards the chronically mentally ill.