Author Question: The best way to determine whether a statistically significant difference in two means is of ... (Read 722 times)

wenmo · **on:** Jul 24, 2018

The best way to determine whether a statistically significant difference in two means is of practical importance is to
a. find a 95 confidence interval and notice the magnitude of the difference.
b. repeat the study with the same sample size and see if the difference is statistically significant again.
c. see if the p-value is extremely small.
d. see if the p-value is extremely large.

Question 2

A newspaper article reported that a large study measured the daily habits of a sample of mid-level managers. The response variable of interest was whether or not the person had a serious illness during the five years of the study. The investigators looked at 30 habits such as smoking, exercise, church attendance, and so on, and for each habit they tested the null hypothesis that the proportions with serious illness were the same for those with and without the habit. The newspaper reported, Only one habit was significantly related to the risk of serious illness. The researchers were surprised to find that the managers who drank tea were significantly more likely to have a serious illness than managers who did not drink tea.. The most likely explanation for this finding is that
a. drinking tea increases the chance of serious illness.
b. there is a confounding variable that both increases the chances of drinking tea and increases the chances of serious illness.
c. people who are prone to illness are likely to prefer tea to other beverages.
d. there were 30 habits examined, so at least one was likely to be significant just by chance, and drinking tea happened to be it.