
Concept explainers
The value of the z-score in a hypothesis test is influenced by a variety of factors. Assuming that all other variables are held constant, explain how the value of z is influenced by each of the following:
a. An increase in the difference between the sample
b. An increase in the population standard deviation.
c. An increase in the number of scores in the sample.
a.

Answer to Problem 1P
The z-score increases with the increase in difference between sample mean and original population mean.
Explanation of Solution
The z-score is,
The z-score is directly proportional to the mean difference. So, increase in mean difference increases the z-value.
b.

Answer to Problem 1P
The z-value decreases with an increase in the population standard deviation
Explanation of Solution
Justification:
The z-value is inversely proportional to the standard deviation. So, increasing the standard deviation, then z-score decreases.
c.

Answer to Problem 1P
The z-value decreases with an increase in the number of scores in sample.
Explanation of Solution
Increasing the number of z-scores in sample, decrease z.
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Chapter 8 Solutions
Essentials of Statistics for the Behavioral Sciences
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