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Stat244 LS Practice Quiz #2
1. It had always been thought that the mean length for a great white shark was 22 feet. Nine great
whites caught off the coast of Australia averaged 24 feet with a standard deviation of 3 feet.
a) Which hypotheses would you use to test the theory that the mean length of great white sharks off the
coast of Australia are longer than great white sharks caught elsewhere?
b) A sample of 10 great white sharks caught off the coast of Australia averaged 24 feet with a
standard deviation of 5 feet. Compute a test statistic under H0. What assumptions do you need
in order to use this test statistic?
Test statistic
Assumptions:
c) Compute the p-value. With α=.05, do you reject or not H0. Make a conclusion in terms of the
researcher’s research interest.
2. Avandia (rosiglitazone maleate) is an oral antidiabetic drug produced by the pharmaceutical
company GlaxoSmithKLine. Before a drug can be prescribed, we must know how the body
absorbs and excretes it. Patients were given a single dose of either 1 milligram (mg) or 2 mg of
rosiglitazone maleate, and the maximum plasma concentration of the drug (in nanograms per
milliliter, ng.ml) was assessed.
Treatment
1 mg
2 mg
n
28
32
𝑥̅
76
150
s
13
42
Is there significant evidence that maximum plasma concentration is dose dependent (higher
doses resulting in higher concentrations)? Use α = 0.01.
Hypotheses:
Test statistic:
Justification of assumptions:
df:
P-value and conclusion:
3. Exercise 17.43
a. Draw a stemplot by hand to check the normality of the difference. (In general, use 5 –
20 stems).
b. Sample mean of the differences = ?? and the sample standard deviation of the
differences is ??. Apply an appropriate test and draw a conclusion in terms of the
original question of interest.
Hypotheses:
Test statistic:
df:
P-value and conclusion: