Question

As degrees of freedom (df) increase, the t distribution

		cannot be measured
		approaches the distribution of raw scores
		becomes more symmetrical
		approaches the standard normal distribution

You perform a two-tailed t-test with an α = .05 comparing the average reaction time to blue and red stimuli. You find that the average reaction time for blue stimuli is M = 5.3 ms and the average reaction time to red stimuli is M = 4.2 ms. The probability value for your t-test is p = .002. What can you conclude?

		You cannot say whether people react faster to one color or the other.
		On average, the reaction time for the two colors is the same.
		On average, people have longer reaction times for blue stimuli than red stimuli.
		On average, people have longer reaction times for red stimuli than blue stimuli.

each person in the sample participated in both the treatment and the control conditions

		repeated measures design
		critical region
		between-subjects design
		alpha

The power of a statistical test increases as

		sample size decreases
		beta increases
		alpha level decreases
		sample size increases

For a one-sample t test if the sample standard deviation is 18 and the standard error of the mean is 3, how many participants were used in this study?

		9
		12
		15
		36

Answer 1

1)approaches the standard normal distribution

2) On average, people have longer reaction times for blue stimuli than red stimuli.

3) repeated measures design

4) sample size increases

5) participants =(18/3)² =36