Statistics Quiz 6

If Joe scored 25 on a test with a mean of 20 and a standard deviation of 5 what is his z-score?

+1.0

An individual at the 50th percentile would have a z score of _____?

0

What percentage of scores falls within three standard deviation of the mean

99.5%

Concluding there is no effect of the independent variable is to the _____ hypothesis, as concluding there is an effect of the independent variable is to the _____ hypothesis.

null; alternative

When using a _____ hypothesis the researcher predicts the direction of the expected difference between the groups.

one-tailed

A directional hypothesis is also known as a _____ hypothesis and a non-directional hypothesis is also known as a _____ hypothesis.

one-tailed; two-tailed

In a study of the effects of exercise on stress, researchers predict simply that there will be a difference in stress level between the exercise and no exercise groups. The researchers are using a _____ hypothesis.

two-tailed

When using a _____ hypothesis the researcher predicts that the groups being compared will differ, but does not predict how they will differ.

two-tailed

Which of the following is an example of a nondirectional hypothesis?

There is a relationship between exercise and increased heart rate.

One and two-tailed hypotheses are both types of _____ hypotheses.

alternative