What are the null and alternative hypotheses in a study designed to assess this? Is this a one- or two-tailed hypothesis test?

In addition to solving the problems, write a 3 – 5 page APA formatted paper explaining the process that lead to the resolution.

 

* Calculators may be used to check answers where calculators are part of assignments but you must show your work and not just state the answers.

 

Chapter 6 exercises

 

4.  In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their stress level on a scale of 1 to 10. The data are provided in the following table.

 

Number of cups of coffee            stress level

 

3                                                          5

 

2                                                          3

 

4                                                          3

 

6                                                          9

 

5                                                          4

 

1                                                          2

 

7                                                          10

 

3                                                          5

 

2                                                          3

 

4                                                          8

 

Calculate a pearson’s r to determine the type and strength of the relationship between caffeine and stress level. How much of the variability in stress scores is accounted for by the number of cups of coffee consumed per day?

 

6. Assuming that the regression equation for relationship between IQ score and psychology exam score is Y’ = 9 + 0. 274, what would you expect the psychology exam score to be for the following individuals given their IQ exam scores?

 

Individual            IQ SCORE (X)      Psychology Exam Score (Y)

 

Tim                       118

 

Tom                      98

 

Tina                      107

 

Tory                      103

 

Chapter 7 Exercises

 

8. The admissions counselors at Brainy University believe that the freshman class they have just recruited is the brightest yet. If they want to test this belief (that the freshmen are brighter than the other classes), what are the null and alternative hypotheses? Is this a one- or two tailed hypothesis test?

 

10. A researcher believes that family size has increased in the past decade in comparison to the previous decade- that is, people are now having more children than they were before. What are the null and alternative hypotheses in a study designed to assess this? Is this a one- or two-tailed hypothesis test?

 

12. Assume that each of the following conclusions represents an error in hypothesis testing. Indicate whether each of the statements is a type I or a type II error.

 

a. based on the date, the null hypothesis is rejected.

 

b. there is no significant difference in quality of care between nurses who work 8 and 12hour shifts.

 

c. there is a significant difference between right and left handers in their ability to perform a spatial task.

 

d. the researcher fails to reject the null hypothesis based on these data.