Dr. Oswald conducts a study examining the relationship between the number of friends one has and the experience of daily stress and life satisfaction. She randomly samples 1,500 elderly men and women in the Memphis, Tennessee, area in the southern United States.
Below are her findings.• Life satisfaction and experience of daily stress: r = -.57 (p = .01)• Number of friends one has and experience of daily stress: r = .09, not sig.• Number of friends one has and life satisfaction: r = .36 (p = .04)Comparing all three correlations, Dr. Oswald will be most able to accurately predict life satisfaction from the experience of daily stress because .a) the relationship is negativeb) the relationship has the largest effect sizec) the relationship was reported firstd) the relationship was statistically significant

 The correct option is B:the relationship has the largest effect size(r=-57)

Explanation:

The ability of Dr. Oswald to predict accurately life satisfaction from the experience of daily stress is hinged on the extent of correlation between the two quantities. Statistically, the relationship between two variables is a measure of their correlation coefficient r. A r value is expected to be between -1 and +1 where r value of -1 or +1 suggests a perfect correlation(i.e. 100% relationship exist).

Therefore, from the findings, the variable with r value closer to -1 or +1 of all three is that which exist between life satisfaction and experience of daily stress. The r value of -.57 means that there is a strong inverse correlation of about 57%  between them looking at the high sample size of 1500.

Again looking at the probability value p associated to this relationship, it is within acceptable standard in the sense that it is less than 0.05.

So Dr. Oswald will be able to predict accurately life satisfaction from the experience of daily stress because there is a good correlation between life satisfaction and experience of daily stress represented by an inverse 57% correlation coefficient and the probability is within limit of 0.05.