4. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in Appendix A in Jackson’s book.

Question

4.	Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in Appendix A in Jackson’s book. 
a.	If Andrew scored 45 on this test. What is his Z score?

b.	If Anna scored 30 on this test. What is her Z score?

c.	If Bill’s Z score was 1.5, what is his real score on this test?

d.	There are 200 students in a sample. How many of these students will have scores that fall under the score of 41?

5.	The table below shows Psychology exam scores, Statistics Exam scores, and IQ scores for a random sample of students. What can you observe in the relationship between IQ and psychology, psychology and statistics, and IQ and statistics? Using a web-calculator, obtain the Pearson’s r and coefficient of determination for the following relationships. 
a.	Between the IQ and psychology scores 
b.	Between the IQ and statistics scores
c.	Between the psychology scores and statistics scores. 
Student number 	IQ 	Psychology	Statistics
101	142	49	49
102	100	30	32
103	103	36	38
104	121	44	41
105	120	35	42
106	115	47	43
107	101	37	35
108	109	45	47
109	111	30	43
110	115	49	46

6.	In a study on caffeine and stress, college students indicated how many cups of coffee they drink per day and their current stress level on a scale of 1 to 10. The table shows the survey results.  Using a web-calculator, obtain the appropriate correlation coefficients. 
Number of cups of coffee	Stress level 
3	5
2	3
4	3
6	9
5	4
1	2
7	10
3	5

Edward · Answer

4. Suppose you administered an anxiety test to a large sample of people and obtained normally distributed scores with a mean of 45 and standard deviation of 4. Do not use web-calculator to answer the following questions. Instead, you need to use the Z distribution table in Appendix A in Jackson’s book.
a. If Andrew scored 45 on this test. What is his Z score?

b. If Anna scored 30 on this test. What is her Z score?

c. If Bill’s Z score was 1.5, what is his real score on this test?

d. There are 200 students in a sample. How many of these students will have scores that fall under the score of 41?