Question 1

Which of the following statements correctly describes the five-number summary of a set of data?

Accepted Answer

A) It includes the mean, standard deviation, first quartile, median, and third quartile. 
B) It includes the mean, median, interquartile range, variance, and standard deviation. 
C) It can be computed from the information in a stemplot. 
D) It includes the minimum, interquartile range, mean, median, and maximum. 
A) It includes the mean, standard deviation, first quartile, median, and third quartile. 
B) It includes the mean, median, interquartile range, variance, and standard deviation. 
C) It can be computed from the information in a stemplot. 
D) It includes the minimum, interquartile range, mean, median, and maximum. C

Question 2

In a study of the function of pectoral fins in fish, a graduate student examined 7 fish with the following lengths (in centimeters, cm):
30 28 29 27 31 25 29
What is the mean length of these 7 fish?

Accepted Answer

A) 28.4 cm 
B) 28.6 cm 
C) 29.0 cm 
D) 29.4 cm 
A) 28.4 cm 
B) 28.6 cm 
C) 29.0 cm 
D) 29.4 cm A

Question 3

A sample of 20 endangered species was obtained and the length of time (in months) since being placed on the list was recorded for each species. The ordered data follow:
52, 54, 58, 59, 59, 60, 60, 63, 65, 66, 67, 68, 69, 73, 74, 77, 78, 79, 79, 98
What is the median length of time (in months) since being placed on the list for these 20 species?

Accepted Answer

A) 66.0 
B) 66.5 
C) 67.0 
D) 67.5 
A) 66.0 
B) 66.5 
C) 67.0 
D) 67.5 B

Question 4

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours).
Which metabolic rate do approximately 75% of the men exceed?

Accepted Answer

A) 1325 
B) 1450 
C) 1575 
D) 1650 
A) 1325 
B) 1450 
C) 1575 
D) 1650

Question 5

By inspection, which of the following sets of numbers has the smallest standard deviation?

Accepted Answer

A) 7, 8, 9, 10 
B) 5, 5, 5, 5 
C) 0, 0, 10, 10 
D) 0, 1, 2, 3 
A) 7, 8, 9, 10 
B) 5, 5, 5, 5 
C) 0, 0, 10, 10 
D) 0, 1, 2, 3

Question 6

If the graph of a distribution of data is skewed, which measure of central tendency is most appropriate?

Accepted Answer

A) Midrange 
B) Median 
C) Mode 
D) Mean 
A) Midrange 
B) Median 
C) Mode 
D) Mean

Question 7

A sample of 20 endangered species was obtained and the length of time (in months) since being placed on the list was recorded for each species. The ordered data follow:
52, 54, 58, 59, 59, 60, 60, 63, 65, 66, 67, 68, 69, 73, 74, 77, 78, 79, 79, 98
What is the mean length of time (in months) since being placed on the list for these 20 species?

Accepted Answer

A) 66.32 
B) 66.50 
C) 67.90 
D) 68.25 
A) 66.32 
B) 66.50 
C) 67.90 
D) 68.25

Question 8

Geckos are lizards with specialized toe pads that enable them to easily climb all sorts of surfaces. A research team examined the adhesive properties of 7 Tokay geckos. Following are the toe-pad areas (in square centimeters, cm2) of this sample:
5.6 4.9 6.0 5.1 5.5 5.1 7.5
What is the first quartile for these data?

Accepted Answer

Question 9

Stream ecologists are interested in the number of distinct organisms found in streams, and whether differences exist based on geography. Separate random samples are obtained from sites in northeastern and southeastern streams, and the number of distinct organisms is recorded for each site. The data are given as separate boxplots for northeastern and southeastern streams.
  Which of the following statements about these data is correct?

Accepted Answer

A) The southeastern plot is skewed to the right. 
B) The northeastern plot is nearly symmetric. 
C) The median number of organisms found in northeastern streams is larger than the median for southeastern streams. 
D) All of these answers are correct. 
A) The southeastern plot is skewed to the right. 
B) The northeastern plot is nearly symmetric. 
C) The median number of organisms found in northeastern streams is larger than the median for southeastern streams. 
D) All of these answers are correct.

Question 10

The following histogram shows the yearly number of unprovoked attacks by alligators on people in Florida over a 33-year period.
  What must be the third quartile of yearly counts of alligator attacks?

Accepted Answer

A) A value in class 12 to 16 
B) A value in class 16 to 20 
C) Exactly 18 
D) A value greater than 14 
A) A value in class 12 to 16 
B) A value in class 16 to 20 
C) Exactly 18 
D) A value greater than 14

Question 11

Researchers measured the length of the central retrix (R1), a flight-involved tail feather, in 21 female long-tailed finches. A boxplot of the length, in millimeters (mm), is given here:
  Based on this boxplot, which of the following statements is TRUE?

Accepted Answer

A) The distribution of R1 lengths is bimodal. 
B) The distribution of R1 lengths has a high outlier. 
C) In this study, 75% of the birds had an R1 length above 70 mm. 
D) The mean R1 length is approximately 66. 
A) The distribution of R1 lengths is bimodal. 
B) The distribution of R1 lengths has a high outlier. 
C) In this study, 75% of the birds had an R1 length above 70 mm. 
D) The mean R1 length is approximately 66.

Question 12

Stream ecologists are interested in the number of distinct organisms found in streams, and whether differences exist based on geography. Separate random samples are obtained from sites in northeastern and southeastern streams, and the number of distinct organisms is recorded for each site. The data are given as separate boxplots for northeastern and southeastern streams.
  What is the approximate value of the median number of distinct organisms found in the sample of northeastern stream?

Accepted Answer

A) The median is approximately the same as for southeastern streams. 
B) The median is approximately 14. 
C) The median is approximately 33. 
D) The median is approximately 37. 
A) The median is approximately the same as for southeastern streams. 
B) The median is approximately 14. 
C) The median is approximately 33. 
D) The median is approximately 37.

Question 13

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines.
What is the first quartile for this data set?

Accepted Answer

A) 7.25 
B) 7.5 
C) 7.75 
D) 8 
A) 7.25 
B) 7.5 
C) 7.75 
D) 8

Question 14

Here is the ordered data of body temperatures (in degrees Fahrenheit) for 65 healthy adult women:
96.4, 96.7, 96.8, 97.2, 97.2, 97.4, 97.6, 97.7, 97.7, 97.8, 97.8, 97.8, 97.9, 97.9, 97.9,
98.0, 98.0, 98.0, 98.0, 98.0, 98.1, 98.2, 98.2, 98.2, 98.2, 98.2, 98.2, 98.3, 98.3, 98.3,
98.4, 98.4, 98.4, 98.4, 98.4, 98.5, 98.6, 98.6, 98.6, 98.6, 98.7, 98.7, 98.7, 98.7, 98.7,
98.7, 98.8, 98.8, 98.8, 98.8, 98.8, 98.8, 98.8, 98.9, 99.0, 99.0, 99.1, 99.1, 99.2, 99.2,
99.3, 99.4, 99.9, 100.0, 100.8
What is the median body temperature according to these data?

Accepted Answer

A) 98.0 
B) 98.35 
C) 98.4 
D) 98.5 
A) 98.0 
B) 98.35 
C) 98.4 
D) 98.5

Question 15

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours).
If 25 points were added to each rate, how would the standard deviation of the new distribution of rates change?

Accepted Answer

A) The standard deviation would increase by 5. 
B) The standard deviation would increase by 25. 
C) The standard deviation would increase by 625. 
D) The standard deviation would remain unchanged. 
A) The standard deviation would increase by 5. 
B) The standard deviation would increase by 25. 
C) The standard deviation would increase by 625. 
D) The standard deviation would remain unchanged.

Question 16

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines.
What is the third quartile for this data set?

Accepted Answer

A) 9 
B) 9.25 
C) 9.5 
D) 10 
A) 9 
B) 9.25 
C) 9.5 
D) 10

Question 17

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours).
Based on this boxplot, which of the following statements is TRUE?

Accepted Answer

A) The distribution of metabolic rates is fairly symmetric. 
B) Approximately half the rates were greater than 1550. 
C) None of the men had a rate less than 1200. 
D) All of these choices are correct. 
A) The distribution of metabolic rates is fairly symmetric. 
B) Approximately half the rates were greater than 1550. 
C) None of the men had a rate less than 1200. 
D) All of these choices are correct.

Question 18

Which of the following data are likely to have a mean that is smaller than the median?

Accepted Answer

A) Right-skewed data 
B) Left-skewed data 
C) Bimodal data 
D) Cyclical data 
A) Right-skewed data 
B) Left-skewed data 
C) Bimodal data 
D) Cyclical data

Question 19

Geckos are lizards with specialized toe pads that enable them to easily climb all sorts of surfaces. A research team examined the adhesive properties of 7 Tokay geckos. Following are the toe-pad areas (in square centimeters, cm2) for this sample:
5.6 4.9 6.0 5.1 5.5 5.1 7.5
Using the correct units, what is the value of the sample variance of toe-pad areas?

Accepted Answer

A) 0.89 cm2 
B) 0.89 cm4 
C) 0.79 cm2 
D) 0.79 cm4 
A) 0.89 cm2 
B) 0.89 cm4 
C) 0.79 cm2 
D) 0.79 cm4

Question 20

Stream ecologists are interested in the number of distinct organisms found in streams, and whether differences exist based on geography. Separate random samples are obtained from sites in northeastern and southeastern streams, and the number of distinct organisms is recorded for each site. The data are given as separate stemplots for northeastern and southeastern streams.
$$\begin{array} { l } 
\text { Northeastern Southeastern } \
005578 \
151123599 \
2039227 \
31478833 \
448841 \
5575 \
\end{array}$$ What is the mean number of distinct organisms recorded for northeastern streams?

Accepted Answer

A) 16.93 
B) 36.93 
C) 37.50 
D) Cannot be determined from the information given 
A) 16.93 
B) 36.93 
C) 37.50 
D) Cannot be determined from the information given

Which of the following statements correctly describes the five-number summary of a set of data?

In a study of the function of pectoral fins in fish, a graduate student examined 7 fish with the following lengths (in centimeters, cm): 30 28 29 27 31 25 29 What is the mean length of these 7 fish?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). Which metabolic rate do approximately 75% of the men exceed?

By inspection, which of the following sets of numbers has the smallest standard deviation?

If the graph of a distribution of data is skewed, which measure of central tendency is most appropriate?

The following histogram shows the yearly number of unprovoked attacks by alligators on people in Florida over a 33-year period. What must be the third quartile of yearly counts of alligator attacks?

Researchers measured the length of the central retrix (R1), a flight-involved tail feather, in 21 female long-tailed finches. A boxplot of the length, in millimeters (mm), is given here: Based on this boxplot, which of the following statements is TRUE?

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines. What is the first quartile for this data set?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). If 25 points were added to each rate, how would the standard deviation of the new distribution of rates change?

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines. What is the third quartile for this data set?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). Based on this boxplot, which of the following statements is TRUE?

Which of the following data are likely to have a mean that is smaller than the median?

Picturing Distributions With Graphs

Scatterplots and Correlation

Regression

Two-Way Tables

Samples and Observational Studies

Designing Experiments

Essential Probability Rules

Independence and Conditional Probabilities

The Normal Distributions

Discrete Probability Distributions

Sampling Distributions

Introduction to Inference

Exercises

Inference About a Population Mean

Comparing Two Means

Inference About a Population Proportion

Comparing Two Proportions

The Chi-Square Test for Goodness of Fit

The Chi-Square Test for Two-Way Tables

Inference for Regression

One-Way Analysis of Variance: Comparing Several Means

More About Analysis of Variance: Follow-Up Tests and Two-Way Anova

Nonparametric Tests

Multiple and Logistic Regression

Filters

Exam 2: Describing Quantitative Distributions With Numbers

Which of the following statements correctly describes the five-number summary of a set of data?

In a study of the function of pectoral fins in fish, a graduate student examined 7 fish with the following lengths (in centimeters, cm): 30 28 29 27 31 25 29 What is the mean length of these 7 fish?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). Which metabolic rate do approximately 75% of the men exceed?

By inspection, which of the following sets of numbers has the smallest standard deviation?

If the graph of a distribution of data is skewed, which measure of central tendency is most appropriate?

The following histogram shows the yearly number of unprovoked attacks by alligators on people in Florida over a 33-year period. What must be the third quartile of yearly counts of alligator attacks?

Researchers measured the length of the central retrix (R1), a flight-involved tail feather, in 21 female long-tailed finches. A boxplot of the length, in millimeters (mm), is given here: Based on this boxplot, which of the following statements is TRUE?

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines. What is the first quartile for this data set?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). If 25 points were added to each rate, how would the standard deviation of the new distribution of rates change?

The following dotplot shows the migraine intensity (on a scale of 1 to 10) for 29 adults suffering from recurring migraines. What is the third quartile for this data set?

A sample was taken of the metabolic rates of men participating in a study regarding diets. The following boxplot depicts these rates (measured in kilocalories per 24 hours). Based on this boxplot, which of the following statements is TRUE?

Which of the following data are likely to have a mean that is smaller than the median?

Picturing Distributions With Graphs

Scatterplots and Correlation

Regression

Two-Way Tables

Samples and Observational Studies

Designing Experiments

Essential Probability Rules

Independence and Conditional Probabilities

The Normal Distributions

Discrete Probability Distributions

Sampling Distributions

Introduction to Inference

Exercises

Inference About a Population Mean

Comparing Two Means

Inference About a Population Proportion

Comparing Two Proportions

The Chi-Square Test for Goodness of Fit

The Chi-Square Test for Two-Way Tables

Inference for Regression

One-Way Analysis of Variance: Comparing Several Means

More About Analysis of Variance: Follow-Up Tests and Two-Way Anova

Nonparametric Tests

Multiple and Logistic Regression

Filters