A researcher is examining whether Omega-3 fish oil supplements improves memory functioning in patients with Alzheimer's Disease. The researcher recruits a random sample of 40 patients. Twenty patients...

A researcher is examining whether Omega-3 fish oil supplements improves memory functioning in patients with Alzheimer's Disease. The researcher recruits a random sample of 40 patients. Twenty patients are given an Omega-3 supplement every day for a month. The other twenty patients are given a placebo (AKA "sugar pill") every day for a month. After the month is over, all 40 participants complete a memory task. Scores on this task range from 1-20, with higher scores indicating better memory functioning. Use the data below to perform anindependent groups t-test.Assume alpha = .05.

Placebo Group:

x-bar: 9.95

s-hat: 1.34

Omega-3 Group:

x-bar: 11.70

s-hat: 0.98

S-hat pooled: 5.25

1) Is this an experimental or non-experimental study?

Group of answer choices

A)Experimental

B) Non-Experimental

2) Is this a between- or within-subjects design?

Group of answer choices

A) Between-Subjects

B) Within-Subjects

3) Write the null and alternative hypotheses:

4) Answer the following questions:

Directional or non-directional?

Alpha?

Degrees of freedom?

Critical value?

5) Find t observed. Hints: this is anindependent groupst-test. Remember that we can not use s-hat pooled as it is, but we have to convert it to s-hatx1-x2 ?

6)Find eta2.

7)Does the Omega-3 supplement significantly improve memory functioning in Alzheimer's patients?

Group of answer choices

A) No

B) Yes