Multiple Choice
Identify the
choice that best completes the statement or answers the question.
|
|
|
1.
|
DDT is an insecticide that accumulates up the food
chain. Predator birds can be contaminated with quite high levels of the chemical by eating many
lightly contaminated prey. One effect of DDT upon birds is to inhibit the production of the enzyme
carbonic anhydrase, which controls calcium metabolism. It is believed that this causes eggshells to
be thinner and weaker than normal and makes the eggs more prone to breakage. (This is one of the
reasons why the condor in California is near extinction.) An experiment was conducted where 16
sparrow hawks were fed a mixture of 3 ppm dieldrin and 15 ppm DDT (a combination often found in
contaminated prey). The first egg laid by each bird was measured, and the mean shell thickness was
found to be 0.19 mm. A “normal” eggshell has a mean thickness of 0.2 mm.
The null and alternative hypotheses are
|
|
|
2.
|
A significance test allows you to reject a
hypothesis  in favor of an alternative Ha at the 5% level of significance. What can you say about significance at
the 1% level?
A) |  can be rejected at the 1% level of
significance. | B) | There is
insufficient evidence to reject  at the 1% level of
significance. | C) | There is
sufficient evidence to accept  at the 1% level of
significance. | D) | Ha can be rejected at the 1% level of significance. | E) | The answer can’t be determined from the information
given. |
|
|
|
3.
|
In a test of H0: µ =
100 against Ha: µ  100, a sample of size 10 produces
a sample mean of 103 and a P-value of 0.08. Thus, at the 0.05 level of
significance
A) | there is sufficient evidence to conclude that
µ  100. | B) | there is sufficient evidence to conclude that µ =
100. | C) | there is insufficient evidence to conclude that
µ = 100. | D) | there is
insufficient evidence to conclude that µ  100. | E) | there is sufficient evidence to conclude that µ =
103. |
|
|
|
4.
|
Which of the following is not a condition
for performing inference about a population mean  ?
A) | Inference is based on n independent
measurements. | B) | The population
distribution is Normal or the sample size is large (say n > 30). | C) | The sample size must be less than 10% of the population
size. | D) | The data are obtained from an SRS from the population of
interest. | E) | Both np and n(1 – p) are 10
or greater. |
|
|
|
5.
|
Resting pulse rate is an important measure of the
fitness of a person's cardiovascular system, with a lower rate indicative of greater fitness.
The mean pulse rate for all adult males is approximately 72 beats per minute. A random sample of 25
male students currently enrolled in the Faculty of Agriculture was selected and the mean resting
pulse rate was found to be 80 beats per minute with a standard deviation of 20 beats per minute. The
experimenter wishes to test if the students are less fit, on average, than the general
population.
A possible Type II error here would be to
A) | conclude that the students are less fit (on average)
than the general population when in fact they have equal fitness on
average. | B) | conclude that the students have the same fitness (on
average) as the general population when in fact they are less fit (on
average). | C) | conclude that the students have the same fitness (on
average) as the general population when in fact they have the same fitness (on
average). | D) | conclude that the students are less fit (on average)
than the general population, when, in fact, they are less fit (on
average). | E) | conclude that the students have the same fitness (on
average) when in fact they are more fit (on average). |
|
|
|
6.
|
Resting pulse rate is an important measure of the
fitness of a person's cardiovascular system, with a lower rate indicative of greater fitness.
The mean pulse rate for all adult males is approximately 72 beats per minute. A random sample of 25
male students currently enrolled in the Faculty of Agriculture was selected and the mean resting
pulse rate was found to be 80 beats per minute with a standard deviation of 20 beats per minute. The
experimenter wishes to test if the students are less fit, on average, than the general
population.
A possible Type I error here would be to
A) | conclude that the students are less fit (on average)
than the general population when in fact they have equal fitness on
average. | B) | conclude that the students have the same fitness (on
average) as the general population when in fact they are less fit (on
average). | C) | conclude that the students have the same fitness (on
average) as the general population when in fact they have the same fitness (on
average). | D) | conclude that the students are less fit (on average)
than the general population, when, in fact, they are less fit (on
average). | E) | conclude that the students have the same fitness (on
average) when in fact they are more fit (on average). |
|
|
|
7.
|
Which of the following conditions are not necessary for the use of the
one-proportion z procedures?
A) | The sample size is at least 30 | B) | the data must be a random sample from the
population of interest | C) | The sample size is less than 10% of the
population size | D) |  | E) |  |
|
|
|
8.
|
You are thinking of using a t-procedure to test hypotheses about the mean of a
population using a significance level of 0.05. You know the population distribution is normal. Which
of the following statements is correct?
A) | You should not use the t-procedure here since the populatiuon mean is less than
30. | B) | You may use the t-procedure here provided you have a sample size that is 30 or
greater. | C) | You may use the t-procedure here with any sample size. | D) | You should not use
the t-procedure here because this is a problem of proportions | E) | You may use the
t-procedure here provided there are no outliers or strong skewness in the sample
data. |
|
|
|
9.
|
An educational researcher is collecting data for a study on the job market for
graduating business majors in 2012. One variable of interest is the percentage of business grads who
were able to find employment in their field within 6 months of obtaining their degree. The researcher
hypothesizes in advance of the study that less than 40% of business grads will be able to find jobs
within 6 months of graduation. To answer this question, one should use
A) | one-proportion z test | B) | one-sample t test | C) | one-sample z
test | D) | one-proportion t test | E) | none of the
above |
|
|
|
10.
|
A random sample survey of 175 skiers at a large European resort found that 28%
of the those surveyed had taken a ski vacation outside their own country within the past year. The
observed value of the test statistic for testing the null hypothesis  versus the
alternative hypothesis  is A) |  | B) |  | C) |  | D) |  | E) | None of the
above |
|