For the first seven questions, refer to the description
below:
In an experiment, a scientist was testing the hypothesis that
subjects' ability to hear faint sounds will improve the more time
they spend unable to see. She made subjects wear a set of goggles
which completely blocked vision for two weeks. During this time,
she had them take daily hearing tests, in which the subjects had to
respond to sounds of varying intensity. On each day, she recorded
the lowest volume which subjects could reliably hear.
1. What are the independent and dependent variables for
this experiment?
Lowest volume subject could hear
How long the subject was wearing goggles
2. Choose the best option to complete the following
statement of the null hypothesis for
this experiment:
"The minimum sound volume that subjects respond to will
["increase", "decrease", "not change"] with more time spent
wearing the goggles."
3. When should the scientist decide what analysis method to
use with her data?
a. Before she begins the experiment
b. Once she gets data from the first subject
c. Once she finishes getting data from all the subjects
d. Once she has looked at the data and can determine which
analysis method would show that her hypothesis is supported
4. Which of these would be a reasonable variable to control
in this experiment? (Choose all correct answers)
a. The zodiacal signs (e.g. Aquarius, Leo, Pisces) of the
subject
b. The subject's previous exposure to loud sounds
c. How well the subject can see before putting on the
goggles
5. The scientist measures sound sensitivity daily with ten
subjects, each of whom wears the goggles for fourteen days. What
statistical test should she use to determine whether the average
minimum volume detected from the ten subjects on day 1 is
significantly different from the average minimum volume detected by
the same subjects on day 14?
a. R-squared
b. Unpaired t test
c. Paired t test
6. When she performs the test to compare day 1 to day 14,
she gets a p-value of 0.075. What does that mean?
a. There is a 7.5% chance that the null hypothesis is true
b. There is a 7.5% chance that the averages on day 1 and day 14
are really different
c. There is a 7.5% chance that the subjects cheated in the
experiment
d. The minimum volume that the subjects could detect was 7.5%
lower on day 14 than on day 1
7. If the scientist wanted to use a control group in this
experiment, which of these would be the best way to do so?
a. Have the same subjects repeat the experiment, and see if it
comes out the same way
b. Have a different group of subjects do the experiment exactly
the same way
c. Have a different group of subjects do the experiment, but
have them wear headgear which blocks their hearing and test their
ability to see faint light
d. Have another group of subjects do the experiment, but without
the goggles, and test their ability to hear faint sounds