QUESTIONS:
1. The following results were observed in a prospective study of the drug Viagra (based on data from Pfizer Inc.) Use the data to answer the following questions:
|
|
Viagra Treatment
|
Placebo
|
|
Headache
|
117
|
29
|
|
No Headache
|
617
|
696
|
a. For those in the Viagra treatment group, find the probability that the subject experienced a headache.
b. Find the risk ratio of a headache for those in the treatment group compared to those in the placebo group. Interpret the result.
c. Determine whether you should evaluate the ARR or the ARI. Then calculate the value of the ARR / ARI for headaches in the treatment and placebo groups. Interpret the result.
d. Find the number of Viagra users that would need to stop using Viagra in order to prevent a single headache and interpret the result.
e. For those in the Viagra treatment group, find the odds in favor of a headache, then find the odds against a headache.
f. Find the odds ratio for headaches in the treatment group compared to the placebo group, and then interpret the result.
- Use EXCEL to answer the following questions.
Please DO NOT use tables!!!
- Please write your answers in "probability form", as defined by the "notation" on page 200.
- HINT: it is very helpful to sketch an individual bell curve for each question, as seen in Figures 5.6 to 5.11 in the textbook (you don't need to present sketches in your submitted homework).
The serum cholesterol levels of all young adults follow a normal distribution with mean 176mg/dL and standard deviation 30 mg/dL.
a. What is the notation for the values "176mg/dL" and "30 mg/dL"?
b. What percentage of young adults has serum cholesterol valuesbetween 186 and 216mg/dL?
c. What percentage of young adults has serum cholesterol valuesabove 186 mg/dL?
d. What percentage of young adults has serum cholesterol valuesbelow 156 mg/dL?
e. Find the 50th percentile.
f. Find the 99th percentile.
g. Find the cholesterol values that bound the middle 99% of data.
h. WITHOUT using a calculator or EXCEL, find the 15th percentile if the 85th percentile is 207mg/dL.