Question

If I took all possible samples of N=50 from the population of undergraduate students in the US, found the mean height for each sample, and plotted the distribution of those sample means, the result would be a

		central limit theorem
		sampling distribution of the mean
		cumulative frequency distribution
		skewed frequency distribution

40 men participating in a study reported how angry they felt at the end of each day for 2 weeks. For the first week 20 of the men were given testosterone supplements and the other 20 were given a placebo. During the 2nd week, the men who were originally given testosterone were switched to the placebo and the men who originally got the placebo were switched to testosterone.

What type of design is this?

		Between Subjects
		Two-way Factorial
		Within Subjects
		Quasi-experimental

40 men participating in a study reported how angry they felt at the end of each day for 2 weeks. For the first week 20 of the men were given testosterone supplements and the other 20 were given a placebo. During the 2nd week, the men who were originally given testosterone were switched to the placebo and the men who originally got the placebo were switched to testosterone.

What is the dependent variable?

		Testosterone supplementation
		Week order
		Anger level
		Gender

Distributions of exam grades are very often skewed because most people score near the high end of the distribution and scores taper off toward the low end. If you have a large population of highly skewed exam grades, and you take a large number of samples of N=50 from that population, calculate the mean for each sample, then plot a frequency distribution of the sample means, what shape will the resulting frequency distribution be? (Hint: think about the Central Limit Theorem)

		Positively skewed
		Normally Distributed
		Binomially Distributed
		The same as the population of scores, negatively skewed

If you give people a questionnaire to measure their computer skills and then you give them the same questionnaire again 6 months later and their answers are nearly the same then the questionnaire has good

		reliability
		predictive validity
		construct validity
		face validity

Answer 1

Here plot shows the distribution of all possible sample means. So it is sampling distribution of sample mean.

Hence, correct option is "sampling distribution of the mean"

-----------------------------

Here each subject is measured twice that is we have paired data. So it is repeated measure or within subject design.

Hence correct option is "Within Subjects"

-----------------------------

Here each subject is measured twice that their anger level is measured. And researcher want to test the effect of treatment on anger level.

Hence correct option is "Anger level"

-----------------------------

Since sample size N =50 is greater than 30 so according to central limit theorem the sampling distribution of sample mean will be approximately normal.

Hence correct option is "Normally Distributed"