A sociologist wants to know about the stress levels in thenation over the past years. In the late 2000s, the average score onthe Brown's Stress Inventory (BSI) in the nation was 19 with astandard deviation of 6.6. A current day sample of 30 produces amean BSI score of 18.4. What can the sociologist concludes with an? of 0.01?

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

b)
Population:
---Select--- current sample the nation the years stress levels theBSI score
Sample:
---Select--- current sample the nation the years stress levels theBSI score

c) Compute the appropriate test statistic(s) tomake a decision about H₀.
(Hint: Make sure to write down the null and alternative hypothesesto help solve the problem.)
critical value =  ; test statistic =
Decision:  ---Select--- Reject H0 Fail to reject H0

d) If appropriate, compute the CI. If notappropriate, input "na" for both spaces below.
[  ,  ]

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

f) Make an interpretation based on theresults.

There has been a significant increase in depression over theyears.There has been a significant decrease in depression over theyears.    There has been no significant changein depression over the years.