Question

The Caffeine Taps dataset contains the results from a double-blind experiment where a sample of male college students were asked to tap their fingers at a rapid rate. The sample was then divided at random into two groups of ten students each. Each student drank the equivalent of about two cups of coffee, which included about 200 mg of caffeine for the students in one group but was decaffeinated coffee for the second group. After a two hour period, each student was tested to measure finger tapping rate (taps per minute). The goal of the experiment was to determine whether caffeine produces an increase in the average tap rate. Although the sample sizes are small, the sample data are roughly symmetric with no strong skewness or outliers. 1. (2 pts) What is the explanatory variable? Is it categorical or quantitative? If it is categorical, list the categories and if it is quantitative, give the units if there are any. 2. (2 pts) What is the response variable? Is it categorical or quantitative? If it is categorical, list the categories and if it is quantitative, give the units if there are any. 3. (2 pts) If you wanted to make inferences about all U.S. adults, what hypothesis would you test? State the null and the alternative hypothesis symbolically and explain what the symbols mean. 4. (2 pts) What is the appropriate theoretical distribution to use to find the $P$-value for the hypothesis test from the previous question? Include the number of degrees of freedom if applicable. 5. (2 pts) It turns out that if the null hypothesis is true, we would obtain sample results at least as extreme as the results we obtained less than 3 times in 1,000. What does that tell you about the $P$-value? 6. (2 pts) It states that the sample was obtained randomly. What does random selection allow you to do? 7. (2 pts) It states that the participants were randomly assigned to caffeine or no caffeine. What does random selection allow you to do?

The Caffeine Taps dataset contains the results from a double-blind experiment where a sample of
male college students were asked to tap their fingers at a rapid rate. The sample was then divided at
random into two groups of ten students each. Each student drank the equivalent of about two cups of
coffee, which included about 200 mg of caffeine for the students in one group but was decaffeinated
coffee for the second group. After a two hour period, each student was tested to measure finger
tapping rate (taps per minute). The goal of the experiment was to determine whether caffeine
produces an increase in the average tap rate.
Although the sample sizes are small, the sample data are roughly symmetric with no strong
skewness or outliers.
1. (2 pts) What is the explanatory variable? Is it categorical or quantitative? If it is categorical,
list the categories and if it is quantitative, give the units if there are any.
2. (2 pts) What is the response variable? Is it categorical or quantitative? If it is categorical, list
the categories and if it is quantitative, give the units if there are any.
3. (2 pts) If you wanted to make inferences about all U.S. adults, what hypothesis would you
test? State the null and the alternative hypothesis symbolically and explain what the symbols
mean.
4. (2 pts) What is the appropriate theoretical distribution to use to find the $P$-value for the
hypothesis test from the previous question? Include the number of degrees of freedom if
applicable.
5. (2 pts) It turns out that if the null hypothesis is true, we would obtain sample results at least
as extreme as the results we obtained less than 3 times in 1,000. What does that tell you
about the $P$-value?
6. (2 pts) It states that the sample was obtained randomly. What does random selection allow
you to do?
7. (2 pts) It states that the participants were randomly assigned to caffeine or no caffeine. What
does random selection allow you to do?

Added by Carol W.

Question

Please give Ace some feedback