Question

For your answers pick one

*A researcher was interested in inspecting the effect of classical music on stress among New York students. She studied a sample of 30 New York students. She found that z= -3.00. Using a = 0.5(two-tailed), what can she conclude?

-Reject the null hypothesis and conclude that classical music has no effect on stress levels
-Reject the null hypothesis and conclude that classical music has no effect on stress levels
-Failed to reject the null hypothesis and conclude that classical music has no effect on stress level
-Failed to reject the null hypotheses and conclude that classical music has an effect on stress level

*Which combination will increase the change to reject the null hypothesis? In other words, which
circumstance will increase the z- score?
-Small standard error, large effect size, and large sample
-Small standard error, large effect size, and small sample
-Large standard error, large effect size, and large sample
-Large standard error, large effect size, and small sample

*A researcher conducts a hypothesis test to evaluate the effect of a treatment that is expected to increase
scores. The hypotheses test product a z- score of z = 2.25. If the researcher is using a two-tailed test,
what is the correct statistical.
-Fail to reject the null hypothesis with either a =.05 or a= .0 1
-Reject the null hypotheses with a=0.5 but not with a = 0.1
-Reject the null hypothesis with either a= .05 or a =.01

*A switch from using a two-tailed test to a one-tailed test, it is easier to reject the null hypothesis.
-False
-Ture

*A sample of n = 25 individuals is selected from a population with u=8- and a treatment is administered to
the sample. What is expected if the treatment has no effect?
-The same mean after the treatment should be very close 80 and should lead you to fail to reject the null
hypothesis
-The sample mean after the treatment should be very close to 80 and should lead you to reject the null
hypothesis.
-The sample mean after the treatment should be very different form 80 and should lead you to reject the
null hypothesis.
-The sample mean after the treatment should be very different from 80 and should lead you to fail to
reject the null hypothesis.

Answer 1

1) p value=NORMSDIST(-3)*2 = 0.0027

-Reject the null hypothesis and conclude that classical music has an effect on stress levels
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2)

-Small standard error, large effect size, and large sample
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3) p value=NORMSDIST(-2.25)*2 = 0.0244

-Reject the null hypotheses with a=0.5 but not with a = 0.1

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4) *A switch from using a two-tailed test to a one-tailed test decrease the p value

so,  it is easier to reject the null hypothesis.

ANswer: TRUE

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5) -The same mean after the treatment should be very close 80 and should lead you to fail to reject the null
hypothesis