A4

For a population with ? = 100 and ? = 20, what is the X value corresponding to z = 1.50? 30115     101.5130

A pharmaceutical company has two possible treatments for arthritis, called Drug A and Drug B.  The company does a matched pairs experiment where they give the two drugs to similar people and then measure their improvement on a scale of 1-50.  The data for a sample of size nine is here: Is there statistically significant evidence at the 0.05 level that Drug B results in more improvement than Drug A?The X for the sample: The S for the sample: The P value  the conclusion

Suppose the relationship between Y and X is given by: Y = 4 + 3.2*X + error  By how much does the expected value of Y change if X increases by 1.29 units? (Round your answer to two decimal places: ex: 123.45)

(6 to 9) The level of cretaine phosphokinase (CPK) in blood samples measures the amount of muscle damage for athletes. At Jock State University, the level of CPK was determined for each of 25 football players and 15 soccer players before and after practice. The two groups of athletes are trained independently. The data summary is as follows :   For football players: n=25 Before Practice After Practice Difference (Before-After) Mean 254.73 225.6 29.13 Standard deviation 115.5 132.6 21.00   For soccer players: n=15 Before Practice After Practice Difference (Before-After) Mean 177.1 173.8 3.3 Standard deviation 60.7 64.4 6.88   Assume that all the data above are normal, use the information above to answer problem (7) Construct a 95% Confidence Interval for the difference in mean CPK values for football players BEFORE and AFTER exercises.

Given the following histogram for a set of data, how many values in the data set are greater than 10.5 but less than 12.5?   A histogram has a horizontal axis labeled Values from 7.5 to 16.5 in increments of 1 and a vertical axis labeled Frequency from 0 to 6 in increments of 1. The histogram has vertical bars of width 1, starting at the horizontal axis value of 7.5. The approximate heights of the bars are as follows, where the horizontal axis label is listed first and the approximate height is listed second: 7.5, 1; 8.5, 2; 9.5, 3; 10.5, 2; 11.5, 3; 12.5, 4; 13.5, 1; 14.5, 5; 15.5, 6.

If n=25, ¯xx¯(x-bar)=47, and s=3, find the margin of error at a 80% confidence levelGive your answer to two decimal places. ________________