A recent study investigated whether vodka is less likely to give you a hangover than wine. Twenty participants on a night out were asked to drink only vodka for the whole evening then rate how they felt the next day out of 10 (0 = I feel fantastic, 10 = I can't move my head in case it explodes). The following month, they were asked to do the same again, only this time they were asked to drink only white wine. The t-score was 2.56. Which of the sentences below is correct?
A)It is significant at the 1% level with a two-tailed test.
B)It is not significant with a two-tailed test.
C)It is significant at the 5% level but not the 1% level with a two-tailed test.
D)It is not significant with a one-tailed test.

Question

Quizplus · Accepted Answer

The t-score of 2.56 corresponds to a p-value of about 0.0145 (using a two-tailed test with 19 degrees of freedom). This means that there is evidence to suggest that there is a difference in hangover ratings between drinking only vodka versus drinking only white wine. Since the p-value is less than 0.05 (i.e. 5%), the result is significant at the 5% level. However, it is not significant at the 1% level (i.e. p-value is greater than 0.01). Therefore, choice C is the correct answer.

A Recent Study Investigated Whether Vodka Is Less Likely to Give