# A psychology researcher who does work in creativity wants to determine whether her sample of 50-year-old adults (N = 150) differs statistically from the population of 50-year-olds in intelligence.

Dear OTA,

Please help me with steps.

Thanks

These problems will follow the hypothesis-testing format that is similar to (but not exactly the same as) the one your textbook uses.

1. A psychology researcher who does work in creativity wants to determine whether her sample of 50-year-old adults (N = 150) differs statistically from the population of 50-year-olds in intelligence. For her sample, she calculates the following: Mean = 109, SD = 10. (Hint: By definition, the mean IQ of this population is 100 and the population standard deviation is 15. Another hint: Use the z-test here!)

A. Null hypothesis:

B. Alternative hypothesis:

C. Statistical test (You can't miss this one!):

D. Significance level (I'll pick it for you; alpha = .05)

E. Critical region for rejecting null hypothesis:

F. Calculate the statistic (please show your work):

G. Decision:

(5 points total)

2. A professor gives his class a final examination that he knows from years of experience yields a population mean of 84. His present class of 24 obtains a mean of 88 and a standard deviation of 8. Is he correct in assuming that the performance of the most recent class differs significantly from that of other classes? Use a one-tailed test here since the professor assumes that the class will score higher.

A. Null hypothesis:

B. Alternative hypothesis:

C. Statistical test:

D. Significance level (I'll pick it for you; alpha = .05)

E. Critical region for rejecting null hypothesis:

F. Calculate the statistic (please show your work):

G. Decision:

(6 points total)

3. An amateur researcher believes that the number of books owned is correlated with emotional intelligence (EQ). She randomly surveys 100 women and 100 men and finds r = .22. What does she conclude?

A. Null hypothesis:

B. Alternative hypothesis:

C. Statistical test:

D. Significance level (I'll pick it for you; alpha = .05)

E. Critical region for rejecting null hypothesis:

F. Calculate the statistic (please show your work):

G. Decision:

https://brainmass.com/statistics/hypothesis-testing/statistics-calculations-for-hypothesis-testing-152497

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