Answer:
A. Negative association, not statistically significant and very weak effect size
B. Negative association, statistically significant and very weak size.
C. Positive association, statistically significant and strong effect size.
Step-by-step explanation:
Cohen's d is an effect size used to indicate the standardised difference between two means. It can be used, for example, to accompany reporting of t-test and ANOVA results. It is also widely used in meta-analysis. Cohen's d is the difference between two group means divided by the pooled standard deviation for the two groups.
A statistically significant result is a result that is always not attributed to chance attributed to chance. The probability value shows the probability of observing the difference if no difference exists.
In statistics , two variables is said to have negative association when the values of one variable seem to decrease as the values of the other variable increase. In statistics, a perfect negative association is represented by the value -1.00, while a 0.00 indicates no association.
A (number of panic attacks in the past month and neuroticism): r = - .03, not sig.
Answer: Negative association, not statistically significant and very weak effect size.
B (number of panic attacks in the past month and number of nightmares in the past month): r = - .14 (p = .05).
Answer: Negative association, statistically significant and very weak size.
C (number of nightmares in the past month and neuroticism): r = .48 (p = .003).
Answer: Positive association, statistically significant and strong effect size.
It is important to note that:
There is covariance because there is presence of significant correlation. You cannot say for a fact about temporal precedence because it is not clear if neuroticism or nightmares came first. You also can't rule out the possibility this relationship is due to a third variable, hence Dr. Moynihan cannot say that neuroticism causes nightmares.
