Homework

For each of the problems below do:

1. State the null and alternative hypothesis.
2. will this be a one tail or two-tail test?.
3. Indicate the type of test to use (Z-test or T-test).
4. Run the given test in R.
5. Report your results on top of a publication quality plot.
6. Describe your conclusion.

Problem 1: Two competing headache remedies claim to give fast-acting relief. An experiment was performed to compare the mean lengths of time required for bodily absorption of brand A and brand B headache remedies. The lengths of time in minutes for the drugs to reach a specified level in the blood were recorded. Results were are follow:

Brand A: Mean time= 21.8 min; sd= 8.7 min; n=500.

Brand B: Mean time= 18.9 min; sd= 7.5 min; n=350.

Are the two drugs different?. Test this at a significance level of 0.05

Problem 2: A consumer group is testing two camp stoves. To test the heating capacity of a stove, it measures the time required to bring 2 quarts of water from 50°F to boiling (at sea level). The following results are obtained:

Model 1: Mean time = 11.4 min; sd= 2.5 min; n= 10 stoves.

Model 2: Mean time = 9.9 min; s2=3.0 min; n=12 stoves.

Assume that the time required to bring water to a boil is normally distributed for each stove. Is there any difference between the performances of these two models? Use a 5% level of significance.