The following are the dosage of medicine and blood AZT concentration levels of 32 healthy adult males

**Dosage **

2.5

2.5

2.5

2.5

2.5

1.9

2.1

1.9

1.9

0.9

1.5

1.4

1.4

1.5

1.8

1.8

2.0

1.8

0.9

0.6

0.9

1.3

1.1

1.4

1.1

0.8

0.7

1.0

1.1

0.8

1.0

0.9

**concentration**

832

672

904

554

996

878

815

805

592

391

710

591

660

694

668

601

77l

757

213

394

391

430

440

352

337

181

174

470

426

170

360

320

1. Describe the above variables using both numerical and graphical methods.

2. Make a stem and leaf display for each variable and use it to describe the each variable’s distribution.

3. Use z-scores to determine if the minimum and maximum values of the variable **AZT concentration **are outliers.

4. Make a scatter plot of the two variables. Use the scatter plot to describe the form of the relationship (if any) between the two variables.

5. Predict the AZT concentration level of a healthy adult male who received a medicine dosage = 2.2. How accurate is your prediction ?

6. Find the correlation coefficient between the dosage of medicine and blood AZT concentration level.

7. Construct the 95 % confidence interval for the mean of blood AZT concentration level.

8. Is there enough evidence at the a = 0.5 significance level that the mean of blood ZT is greater than 450?