Z-Score Problems

Using a normal curve table, give the percent of scores above Z = +.87

Using a normal curve table, give the percent of scores above Z = -2.29

Using a normal curve table, give the percent of scores below Z = -1.22

Using a normal curve table, give the percent of scores between Z = -.22 and Z = +.34

Using a normal curve table, give the percent of scores between Z = -2.00 and Z = +2.08

Assuming a normal curve, if a person is in the top 2.39% of the country on verbal ability, what is the lowest Z score this person could have?

Z-Score Problems (Chapter 5)

Based on the information given for each of the following studies, decide whether to reject the null hypothesis. Note: N=1. For each, state/calculate: 1) Zcritical, 2) Zcalculated, and 3) the conclusion (Reject Ho/Accept Ho).

(a)

(b)

(c)

Hypothesis Testing (Chapter 5)

A randomly selected person, after going through an experimental education program, receives a score of 90 on a standardized aptitude test. The scores of people in general on this standardized aptitude test are normally distributed with a mean of 85 (M=85) and a standard deviation of 10 (SD=10.). The researcher predicted that that the experimental education program will lead to an increase in scores on the standardized aptitude test. Test at the .05 significance level (p

Step 1 (State the null and research hypothesis):

H0:

H1:

Step 2 (Determine the characteristics of the comparison distribution):

Step 3 (Determine Zcritical, or the cutoff score on the comparison distribution at which the null hypothesis should be rejected):

Step 4 (Determine Zcalculated, or your samples score on the comparison distribution):

Step 5 (Decide whether to accept or reject the null hypothesis)