Download Chapters1to4MultipleChoicePractice

AP Statistics
Name_______________________________________________
Multiple Choice Practice: Chapters 1-4
Mr. Coppock/Mr. Dooley
1.) A researcher reports that, on average, the participants in his study lost 10.4 lbs. after two months on
his new diet. A friend of yours comments that she tried the diet for two months and lost no weight, so
clearly the report was a fraud. Which of the following statements is correct?
(a) Your friend must not have followed the diet correctly, since she did not lose weight.
(b) Since your friend did not lose weight, the report must not be correct.
(c) The report only gives the average. This does not imply that all participants in the study lost
10.4 lbs. or even that all lost weight. Your friend’s experience does not necessarily contradict the
study results.
(d) In order for the study to be correct, we must now add your friend’s results to those of the study
and recompute the new average.
2.) If you are told that a data set has a mean of 25 and a variance of 0, you can
conclude that:
(a) There is only one observation in the data set
(b) There are no observations in the data set
(c) All of the observations in the data set are 25
(d) Someone has made a mistake
(e) None of the above
3.) Of the following measures: mean, median, IQR, and standard deviation, which are resistant?
(a) Mean and median
(b) Median and IQR
(c) Mean and standard deviation
(d) Median and standard deviation
(e) None of the above
4.) The heights of American men aged 18 to 24 are approximately normally distributed with mean 68
inches and standard deviation 2.5 inches. Half of all young men are shorter than
(a) 65.5 inches
(b) 68 inches
(c) 70.5 inches b
(d) Can’t tell, because the median height is not given
(e) None of the above
5.) Use the information in the previous problem. Only about 5% of young men have heights outside the
range:
(a) 65.5 inches to 70.5 inches
(b) 63 inches to 73 inches
(c) 60.5 inches to 75.5 inches
(d) 58 inches to 78 inches
(e) None of the above
6.) A smooth curve which approximates the shape of a histogram and describes the overall pattern of a
distribution is called
(a) A stemplot
(b) A normal plot
(c) A normal probability plot
(d) A density curve
(e) None of the above
7.) Suppose that sixteen-ounce bags of chocolate chip cookies are produced with an
actual mean weight of 16.1 ounces and a standard deviation of 0.1 ounce. Assume weights are normally
distributed. The percentage of bags that will contain between 16.0 and 16.1 ounces is
(a) 10
(b) 16
(c) 34
(d) 68
(e) None of the above
8.) The plot shown is a normal probability plot for a set of data. The data value is plotted on the x-axis,
and the standardized value is plotted on the y-axis. Which statement is true for this data set?
(a) The data are clearly normally distributed.
(b) The data are approximately normally distributed.
(c) The data are clearly skewed to the right.
(d) The data are clearly skewed to the left.
(e) There is insufficient information to determine the
shape of the distribution.
9.) Popl and Pop2 are normal density curves with means and standard deviations 1 , 1 and 2 ,  2
respectively. Suppose that 1  2 and 1  2 2 Consider these statements:
I.
II.
III.
Popl has twice as many observations within one standard deviation as Pop 2.
The density curve for Popl is taller than that of Pop2.
The density curves are centered around different numbers.
Which of these statements are correct?
(a) I only
(b) II only
(c) III only
(d) I and II only
(e) None of the above gives the correct set of true responses.
10.) In a statistics course, a linear regression equation was computed to predict the final exam score from
the score on the first test. The equation was y = 10 + .9x where y is the final exam score and x is the score
on the first test. Carla scored 95 on the first test. What is the predicted value of her score on the final
exam?
(a) 95
(b) 85.5
(c) 90
(d) 95.5
(e) None of the above
11.) Refer to the previous problem. On the final exam Carla scored 98. What is the value of her residual?
(a) 98
(b) 2.5
(c) -2.5
(d) 0
(e) None of the above
12.) All but one of the following statements contains a blunder. Which statement is correct?
(a) There is a correlation of 0.54 between the position a football player plays and their weight.
(b) The correlation between planting rate and yield of corn was found to be
r = 0.23.
(c) The correlation between the gas mileage of a car and its weight is r = 0.71MPG.
(d) We found a high correlation (r = 1.09) ) between the height and age of children.
(e) We found a correlation of =0.63 between gender and political party affiliation.
13.) What does the square of the correlation (r2) measure?
(a) The slope of the least-squares regression line
(b) The intercept of the least-squares regression line
(c) The extent to which cause and effect is present in the data
(d) The fraction of the variation in the values of y that is explained by least-squares regression of y
on x
(e) None of the above
14.) Which of the following statements are true?
I. Correlation and regression require explanatory and response variables.
II. Scatterplots require that both variables be quantitative.
III. Every least-squares regression line passes through ( x , y )
(a) I and II only
(b) I and III only
(c) II and III only
(d) I, II, and III
(e) None of the above
15.) A local community college announces the correlation between college entrance exam grades and
scholastic achievement was found to be -1.08. On the basis of this you would tell the college that
(a) The entrance exam is a good predictor of success.
(b) The exam is a poor predictor of success.
(c) Students who do best on this exam will be poor students.
(d) Students at this school are underachieving.
(e) The college should hire a new statistician.
16.) The following are resistant:
(a) Least-squares regression line
(b) Correlation coefficient
(c) Both the least-squares line and the correlation coefficient
(d) Neither the least-squares line nor the correlation coefficient
17.) The effect of removing the right-most point (near the positive x-axis) in the
scatterplot shown would be:
(a) The slope of the LSRL will increase; r will increase
(b) The slope of the LSRL will increase; r will decrease
(c) The slope of the LSRL will decrease; r will increase
(d) The slope of the LSRL will decrease; r will decrease
(e) No change
18.) Suppose the correlation between two variables x and y is due to the fact that both
are responding to changes in some unobserved third variable. What is this due to?
(a) Cause and effect between x and y
(b) The effect of a lurking variable
(c) Extrapolation
(d) Common sense
(e) None of the above.
19.) Which of the following are true statements?
I. High correlation does not necessarily imply causation.
II. A lurking variable is a name given to variables that cannot be identified or explained.
III. Successful prediction requires a cause and effect relationship.
(a) I only
(b) II only
(c) III only
(d) I and III only
(e) None of the above.
20.) The z-score and percentile are measures of
a) relative frequency
b) location
c) relative location
d) variability
e) approximate normality
21.) Suppose I have a set of data with 5 numbers: -6.0, -4.5, 0, 5.0, and an unknown 5th number. For
these 5 data points, which of the following statistics can NEVER be greater than zero?
a)
b)
c)
d)
the mean
the standard deviation
the interquartile range
the median
22.) Suppose that a frequency distribution and a cumulative frequency distribution are constructed from
the same set of data, using the same classes. Then, for each class,
a) the frequency  the cumulative frequency
b) the frequency  the cumulative frequency
c) the frequency  the cumulative frequency
d) the cumulative frequency  the frequency
e) the cumulative frequency  the frequency
23.) A distribution can have more than one
a) mean
b) interquartile range
c) standard deviation
d) mode
e) median
24.) Suppose that for a set of numeric data, the standard deviation is less than 1.0. Then it must be true
that
a)
b)
c)
d)
the variance < the standard deviation.
the variance  the standard deviation.
the variance  the standard deviation.
the standard deviation  the variance.
e) the standard deviation  the variance.
In a study of male / female differences in carnivores, the height of the canine teeth in the lower jaws were
measured. The data below are graphic representations of these data. Use these graphs to answer
questions 25.) and 26.) below.
Boxplot and histogram of Lower canine tooth height (mm)
Stemplot of Lower canine tooth height (mm) N = 18
0|99
1|0111223344
2|4
3|03
4|014
Key 1│4 = 14 mm
25.) The median of the lower jaw canine tooth heights is:
a) 10
b) 11
c) 12
d) 13
e) 14
26.) Considering the graphic displays, the best description of these data would be:
a)
b)
c)
d)
e)
Skewed left
Skewed right
Symmetric
Bimodal
Light tailed
27) In a recent study a researcher asked an SRS of Darien residents what percentage of their household
income they donate to charity. The researcher then plotted the residents’ income on the x-axis and the
percentage they give to charity on the y-axis. He found the scatterplot to be linear with a correlation of r =
0.9. What conclusion can one draw from this study:
I. The higher the income in the household, the more likely that household is to give a higher percentage of
its income to charity
II. Having more money causes you to give a higher percentage of your income to charity
III. We can’t assume that higher household income causes one to give a higher percentage of one’s
household income to charity because this was an observational study not an experiment
IV. We can predict quite well what percentage of one’s household income they give to charity given their
household income by looking at a regression equation model.
V. Being more charitable causes a household to earn more money (perhaps due to Devine reward)
a) I only
b) I, II
c) I, II, III
d) I, III, IV
e) All five options are reasonable conclusions from the study
Solutions:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
c
c
b
b
b
d
c
c
e
d
b
b
d
c
e
d
a
b
a
c
d
b
d
b
d
b
d