Download File - AP Statistics

Name: ______________________________________________ Due: 2/21/17
AP Statistics: Chapter 7 Test (MC)
Directions: Write the letter of the best choice on the line. Show all your work. Indicate clearly the methods
you use.
_______________________________________________________________________________________
_____1. Following a dramatic drop of 500 points in the Dow Jones Industrial Average in September 1998, a
poll conducted for the Associated Press found that 92% of those polled said that a year from now their family
financial situation will be as good as it is today or better. Which of the following terms describes the number
92%?
(a) statistic.
(b) sample.
(c) sample parameter.
(d) population parameter.
(e) population.
_____2. What is distribution of values taken by a statistic in all possible samples of the same size from the
same population called?
(a) the probability that the statistic is obtained.
(b) the population parameter.
(c) the variance of the values.
(d) the sampling distribution
(e) the distribution of sample data.
_____3. The best statistic for estimating a parameter has which of the following characteristics?
(a) Low bias, high variability.
(b) High bias, high variability.
(c) Low bias. Since a statistic should always equal the parameter it is estimating, there should be no
variability.
(d) Low bias, low variability.
(e) Low bias, high variability.
_____4. A student investigating study habits asks a simple random sample of 16 students at her school how
many minutes they spent on their English homework the previous night. Suppose the actual parameter
values for this variable are 𝜇 = 45 minutes and 𝜎 =15minutes. Which of the following best describes what
we know about the sampling distribution of means for the student’s sample?
(a) 𝜇𝑥̅
(b) 𝜇𝑥̅
(c) 𝜇𝑥̅
(d) 𝜇𝑥̅
(e) 𝜇𝑥̅
=45; 𝜎𝑥̅ unknown; shape of distribution unknown
=45; 𝜎𝑥̅ =15; distribution approximately Normal
=45; 𝜎𝑥̅ =15; shape of distribution unknown
=45; 𝜎𝑥̅ =3.75; distribution approximately Normal
=45; 𝜎𝑥̅ =3.75; shape of distribution unknown
𝜎
_____5. In order to use the formula 𝑛 to calculate the standard deviation of the sampling distribution of the
√
sample mean, which of the following conditions must be met?
I.
II.
III.
𝑛 ≥ 30
The population’s distribution is approximately Normal.
The sample size is less than 10% of the population size.
(a) I only
(b) II only
(c) III only
(d) III and either I or II
(e) All three conditions must be met.
_____6. You take an SRS of size 500 from the 37,000 students at Purdue University and measure their
heights. You then take an SRS of size 500 from the 4,400,000 adults in the state of Indiana and measure their
heights. Assuming the standard deviation of individual heights in the two populations is the same, the
standard deviation of the sampling distribution of mean heights for the Indiana sample is
(a) approximately the same as for the Purdue sample because both are samples of size 500.
(b) smaller than for the Purdue sample because the population of Indiana is much larger.
(c) larger than for the Purdue sample because the population of Indiana is much larger.
(d) larger, because the Indiana sample is smaller relative to the population from which it’s been taken.
(e) either larger or smaller than for the Purdue sample because it varies from sample to sample.
_____7. In a large population of adults, the mean IQ is 112 with a standard deviation of 20. Suppose 200
adults are randomly selected for a market research campaign. The sampling distribution of the sample mean
IQ is
(a) exactly Normal, mean 112, standard deviation 20.
(b) approximately Normal, mean 112, standard deviation 0.1.
(c) approximately Normal, mean 112, standard deviation 1.414.
(d) approximately Normal, mean 112, standard deviation 20.
(e) exactly Normal, mean 112, standard deviation 1.414.
_____8. In a study of the effects of acid rain, a random sample of 100 trees from a particular forest is
examined. Forty percent of these show some signs of damage. Which of the following statements is correct?
(a) The sampling distribution of the sample proportion of damaged trees is approximately Normal.
(b) If we took another random sample of trees, we would find that 40% of these would show some signs of
damage.
(c) If a sample of 1000 trees was examined, the variability of the sampling distribution of the sample
proportion would be larger than in a sample of 100 trees.
(d) The standard deviation of the sampling distribution of the sample proportion of damaged trees is
√100(0.4)(0.6).
(e) None of the above statements is correct.
𝑝(1−𝑝)
_____9. In order to use the formula √
𝑛
to calculate the standard deviation of the sampling distribution
of the sample proportion, which of the following conditions must be met?
I. np ≥10 and n(1- p) ≥ 10
II. The population’s distribution is approximately Normal.
III. The sample size is less than 10% of the population size.
(a) I only
(b) II only
(c) III only
(d) I and III
(e) All three conditions must be met.
_____10. Which of the following statements is/are true when taking an SRS from a large population?
𝜎
I. The sampling distribution of 𝑥̅ has standard deviation 𝑛 even if the population is not Normally distributed.
√
II. The sampling distribution of x is Normal if the population has a Normal distribution.
III. When n is large, the sampling distribution of x is approximately Normal even if the population is not
Normally distributed.
(a) I and II
(b) I and III
(c) II and III
(d) I, II, and III
(e) None of the above gives the correct set of responses.
_____11. The graph below shows the sampling distribution of the sample mean for samples of two different
sizes. Which of the following statements is true?
(a)
(b)
(c)
(d)
(e)
The sample size of I is less than the sample size of II.
The sample size of I is greater than the sample size of II.
The sample size of I is equal to the sample size of II.
The sample size does not affect the sampling distribution.
The sample sizes cannot be compared from the graphs.
_____12. According to the DuPont 2007 Global Automotive Color Popularity Report, 19% of all cars
manufactured in 2007 were white. In a random sample of 100 cars parked in long-term parking at
Philadelphia International Airport, 22% of the cars were white. Which of the following statements is true?
(a) 19% and 22% are parameters, 100 is a statistic.
(b) 19% is a parameter, 22% is a statistic.
(c) 19% is a statistic, 22% is a parameter.
(d) 19% and 22% are statistics, 100 is neither a parameter nor a statistic.
(e) 19%, 22%, and 100 are all statistics.