MATH220 quiz 1
1. Mark whether the following statements are true or false.
(a) If a sample is chosen such that every individual in the population has
an equal chance of being selected, then this sample must be a simple
random sample.
False
(b) A person’s weight is a continuous variable.
True
(c) A case control study is an observational study.
True
(d) Observational studies are generally more reliable than randomized
experiments.
False
(e) A confounder makes it easier to draw conclusions from a study.
False
2. Multiple choice. Circle the correct answer for each problem.
(a) Police at a sobriety checkpoint pull over every fifth car to determine
whether the driver is sober. This is a
a) stratified sample b) cluster sample c) systematic sample
c)
(b) A medical doctor gave a new drug to 80 flu patients. After a week
75 of the patients got well. He claimed the drug was effective. What
is the major drawback of this study? Choose only one answer, and
pick out only the major drawback.
a). The sample size is too small.
b). The experiment has no control group for comparison.
c). The experiment is not randomized.
d). The experiment is not double blind.
b)
(c) A medical researcher wants to test of effect of a new drug. He recruited 200 patients. He selected the first 100 patients on the sign up
list and gave them the new drug. The remaining 100 patients were
given the placebo. What is major drawback of this study?
a). The sample size is too small.
b). The experiment has no control group for comparison.
c). The experiment is not randomized.
d). The experiment is not double blind.
c)
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(d) In a recent poll, 50% said they supported a school bond issue. The
number 50% is a
a) parameter
b) statistic
b)
(e) (optional) The chair needs to choose 3 professors from 5 professors
(A, B, C, D, E) to form a committee. In how many ways can he form
the committee?
a) 10 b) 25 c) 75 d) 20.
a).
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