Question

An educational psychologist wants to know if a popular new hypnosis technique impacts depression. The psychologist collects a sample of 15 students and gives them the hypnosis once a week for two months. Afterwards the students fill out a depression inventory in which their mean score was 50.55. Normal individuals in the population have a depression inventory mean of 51 with a standard deviation of 3.1. What can be concluded with α = 0.01?

a) What is the appropriate test statistic?
---Select--- na z-test OR one-sample t-test OR independent-samples t-test OR related-samples t-test

b)
Population:
---Select--- students receiving hypnosis OR normal individuals OR two months OR new hypnosis technique
Sample:
--Select--- students receiving hypnosis OR normal individuals OR two months OR new hypnosis technique

c) Obtain/compute the appropriate values to make a decision about H₀.
(Hint: Make sure to write down the null and alternative hypotheses to help solve the problem.)
critical value = ________ ; test statistic = ________
Decision:  ---Select--- Reject H0 OR Fail to reject H0

d) If appropriate, compute the CI. If not appropriate, input "na" for both spaces below.
[________ ,________ ]

e) Compute the corresponding effect size(s) and indicate magnitude(s).
If not appropriate, input and select "na" below.
d = ________;   ---Select--- na OR trivial effect OR small effect OR medium effect OR large effect
r² = ________;   ----Select--- na OR trivial effect OR small effect OR medium effect OR large effect

f) Make an interpretation based on the results.

A) The depression of students that underwent hypnosis is significantly higher than the population.

B) The depression of students that underwent hypnosis is significantly lower than the population.    

C) The new hypnosis technique does not significantly impact depression.

Answer 1