PART 1. CHOOSE A PROCEDURE
1. A manager noticed that orders at their restaurant contained about 50 calories less after
calorie counts were included on the menu. Before they were
included, the average calorie
count per order was 650. A random sample of 51 orders after calorie counts were
added had
an average calorie count of 557 with a standard deviation of
298. The sample distribution is
right-skewed.
a. The population of interest is
and the sample is
The variable is
quantitative
categorical
which is (circle one)
and has units of
experiment.
This is an (circle one) observational study
b. To determine whether this result is significant, we should use a (circle one)
confidence interval hypothesis test.
c. Based on the information given, we (circle one)
cedure.
can
cannot
use a t-pro-
2. Elevated eosinophils are often a sign of heightened allergic response. In a study, eosinophil
level was measured in 350 subjects with severe allergies after they took a new drug designed
to alleviate severe allergic symptoms. The units are K/mcg. For the 350 subjects, the mean
was 0.4 K/mcg with a standard deviation of 0.08 K/mcg. To determine whether this
vides evidence that the eosinophil level is below 0.45, circle the appropriate choices below.
a. The population of interest is
and the sample is
pro-
The variable is
which is (circle one)
quantitative
categorical
This is an (circle one)
and has units of
observational study
experiment.
should use a (circle one)
confidence interval
b. To determine whether this provides evidence that the eosinophil level is below 0.45, we
c. Based on the information given, we (circle one)
hypothesis test.
can
cannot
use a t-pro-
cedure.
d. Results will be (circle one) similar
different
than t.
if we use a z-procedure rather