Question

A researcher was interested in the relationship between the reported stress level (variable X) and performance on memory test (variable Y).

The data collected on a sample of n = 62  undergraduate students produced the following results: M_X = 4, SSx = 30, M_Y = 6, SS_Y= 90, and SP = - 15

A. Is there a significant correlation between stress level and memory performance? Assume 2-tailed test, p < .05. For full credit your answer should include:

Null and alternative hypotheses

Computation of Person correlation, r

The r critical for this study and the decision about the null hypothesis

The conclusion with the Person correlation outcome in APA style

B. Find the regression equation for predicting memory performance (Y) from the person's reported stress level (X). (Note: For full credit write all computational steps in your answer)

Answer 1

A)

Null hypothesis:Ho: =0

alternate hypothesis:Ho: 0

Person correlation, r =SP/sqrt(SSx*SSy)=-15/sqrt(30*90)=-0.289

for 0.05 level and (n-2=60) df critical r=0.250

as absolute value of tst statsitic r is higher then critical value we reject null and conclude that  there a significant correlation between stress level and memory performance

b)

here slope b1=SP/SSx=-15/30=-0.5

and intercept bo=My-b1*Mx=6-(-0.5)*4=8

hence memory performance (Y)=8-0.5*stress level(X)