Since its removal from the banned substances list in 2004 by the World Anti-Doping Agency, caffeine has been used by athletes with the expectancy that it enhances their workout and performance. Many studies have been conducted to assess the effect of caffeine on athletes, but few look at the role ti plays in sedentary females. Researchers at the University of Western Australia conducted a test in which they determined the rate of energy expenditure (kilojoules) on 10 healthy, sedentary females who were non-regular caffeine users. Each female was randomly assigned either a placebo or caffeine pill (6mg/kg) 60 minutes prior to exercise. The subject rode an exercise bicycle for 15 minutes at 65% of their maximum heart rate, and the energy expenditure was measured. The process was repeated on a separate day for the remaining treatment. The mean difference in energy expenditure (caffeine-placebo) was 18 kJ with a standard deviation of 19 kJ.

1) Describe the sample data set and identify the variable being measured

2) Which type of hypothesis test would be most appropriate for this set of data?

3) Describe the population from which your sample was obtained. What should be the value of the population parameter and why?

4) Do you think your data comes from a random sample? Why /why not?

5) What other condition must you check in order to perform the hypothesis test?

6) Describe the null and alternative hypothesis for your hypothesis test against the value

7) Determine the test statistic

8) Calculate the p-value for this hypothesis test

9) State your conclusion from this hypothesis test. What happens to the null hypothesis?