Describe a study that would provide more useful information.

The most appropriate study design depends, among other things, on the distribution of
1.A) The risk factor in the population of interest
2.B) The participants
3.C) The outcome in the population of interest
4.D) $A\mathrm{\&}C$

A researcher is conducting a study to examine the effects of cognitive behavior therapy for the treatment of social anxiety in a sample of 16 participants. He measures the social anxiety scores of participants before the tratment and then again after treatment and the resulting data is as follows:
$n=16,M_0=5,s=4$
a) What type of design is this study (single-sample, independent measures, repeated measures)
b)State the null and alternate hypotheses
c) Using an ${\displaystyle \alpha levelof.05(\alpha =.05)}$, identify the critical values of t for a 2-tailed test.

B. Given the population 1, 2, 3, 4, 6, and 8. Suppose sample size of 3 are drawn from this 
population.
4. What is the mean ( 𝜇 ) and the variance ( 𝜎
2
) of the population?
5. How many different sample size n = 3 can be drawn from this population? List them with 
their corresponding means.
6. What is the mean ( 𝜇X̅ ) and the variance ( 𝜎
2
X̅ ) of the sampling distribution of the sample 
mean?