Question 1

The value of the mean times the number of observations equals the sum of all of the observations.

Accepted Answer

A) True 
 B)False

Question 2

Measures of variability are numbers that indicate the spread or scatter of observations; they show the extent to which individual values in a data set differ from one another and, hence, differ from their central location.

Accepted Answer

A) True 
 B)False

Question 3

Number of Calories in Soft Drinks
The following data represent the number of calories in 340 mL cans of a sample of 8 popular soft drinks: 124, 144, 147, 146, 148, 154, 150, and 234.
-Refer to the Number of Calories in Soft Drinks statement. Construct a box plot for these data. Does the box plot indicate the presence of any outliers?

Accepted Answer

@#IMG-DLM& Yes, the observation 124 is a suspect o

Question 4

A student scores 89, 75, 94, and 88 on four exams during the semester and 97 on the final exam. If the final is weighted double and the four others weighted equally, the student's final average would be 90.

Accepted Answer

A) True 
 B)False

Question 5

Manufacturing Operation Time
In a time study conducted at a manufacturing plant, the length of time to complete a specified operation is measured for each one of n = 40 workers. The mean and standard deviation are found to be 15.2 and 1.40, respectively.
-Refer to the Manufacturing Operation Time statement. Describe the sample data using Tchebysheff's Theorem.

Accepted Answer

If you doubt that the distribution of me

Question 6

The 10th percentile of a set of measurements is the value that exceeds 90% of the measurements and is less than the remaining 10% of the measurements.

Accepted Answer

A) True 
 B)False

Question 7

Suppose the standard deviation for a given sample is known to be 12. If each data value in the sample is multiplied by 3, the standard deviation will be 36.

Accepted Answer

A) True 
 B)False

Question 8

One of the advantages of the standard deviation over the variance as a measure of variability is that the standard deviation is measured in the original units.

Accepted Answer

A) True 
 B)False

Question 9

The standard deviation is always smaller than the variance.

Accepted Answer

A) True 
 B)False

Question 10

If two data sets have the same range, which of the following characteristics do these data sets also share?

Accepted Answer

A)  The distances from the smallest to the largest observations in both sets will be the same. 
B)  The smallest and largest observations will be the same in both sets. 
C)  They will have the same variance. 
D)  They will have the same interquartile range. 
A)  The distances from the smallest to the largest observations in both sets will be the same. 
B)  The smallest and largest observations will be the same in both sets. 
C)  They will have the same variance. 
D)  They will have the same interquartile range.

Question 11

The mean is a measure of the middle centre of a distribution.

Accepted Answer

A) True 
 B)False

Question 12

Which of the following represents a disadvantage of using the sample range to measure dispersion?

Accepted Answer

A)  It produces spreads that are not meaningful for data analysis. 
B)  The largest or smallest observation (or both) may be an outlier. 
C)  The sample range is not measured in the same units as the data. 
D)  The sample range is measured in the same units as the data. 
A)  It produces spreads that are not meaningful for data analysis. 
B)  The largest or smallest observation (or both) may be an outlier. 
C)  The sample range is not measured in the same units as the data. 
D)  The sample range is measured in the same units as the data.

Question 13

Which of the following statements about the mean is NOT always correct?

Accepted Answer

A)  The sum of the deviations from the mean is 0. 
B)  Half the observations are on either side of the mean. 
C)  The mean is a measure of the middle of a distribution. 
D)  The value of the mean times the number of observations equals the sum of all of the observations. 
A)  The sum of the deviations from the mean is 0. 
B)  Half the observations are on either side of the mean. 
C)  The mean is a measure of the middle of a distribution. 
D)  The value of the mean times the number of observations equals the sum of all of the observations.

Question 14

Which of the following is the most frequently used measure of variation?

Accepted Answer

A)  the mean 
B)  the range 
C)  the variance 
D)  the standard deviation 
A)  the mean 
B)  the range 
C)  the variance 
D)  the standard deviation

Question 15

Which of the following statements describes the variance of a data set?

Accepted Answer

A)  The variance is a mean of absolute deviations. 
B)  The variance is a mean of positive and negative deviations. 
C)  The variance is a mean of squared deviations. 
D)  The variance is a mean of only the positive deviations. 
A)  The variance is a mean of absolute deviations. 
B)  The variance is a mean of positive and negative deviations. 
C)  The variance is a mean of squared deviations. 
D)  The variance is a mean of only the positive deviations.

Question 16

Cracks in Bar
The following data represent the number of small cracks per bar for a sample of eight steel bars: 4, 6, 10, 1, 3, 1, 25, and 8.
-Refer to Cracks in Bar statement. Which, if any, of the observations appear to be outliers? Justify your answer.

Accepted Answer

The value 25 has a z

Question 17

A sample of 2500 vehicles in Minnesota showed the following statistics related to the number of accidents per month:     and   Based on these data, we can conclude that the distribution of accidents is skewed.

Accepted Answer

A) True 
 B)False

Question 18

A sample of n = 10 measurements consists of the following values: 15, 12, 13, 16, 11, 12, 14, 15, 11, and 13.
a. Can you use Tchebysheff's Theorem to describe this data set? Why or why not?
b. Can you use the Empirical Rule to describe this data set? Why or why not?

Accepted Answer

a. Yes, since the da

Question 19

Suppose that a particular statistical population can be described, at least roughly, by the normal curve. Which of the following can we use to estimate the percentages of all population values that lie within specified numbers of standard deviations from the mean?

Accepted Answer

A)  Tchebysheff's Theorem 
B)  the Empirical Rule 
C)  the interquartile range 
D)  a box plot 
A)  Tchebysheff's Theorem 
B)  the Empirical Rule 
C)  the interquartile range 
D)  a box plot

Question 20

In a histogram, what may be said of the proportion of the total area that must be to the right of the mean?

Accepted Answer

A)  It is less than 0.50 if the distribution is skewed to the left. 
B)  It is always exactly 0.50. 
C)  It is more than 0.50 if the distribution is skewed to the right. 
D)  It is exactly 0.50 only if the distribution is symmetric. 
A)  It is less than 0.50 if the distribution is skewed to the left. 
B)  It is always exactly 0.50. 
C)  It is more than 0.50 if the distribution is skewed to the right. 
D)  It is exactly 0.50 only if the distribution is symmetric.

The value of the mean times the number of observations equals the sum of all of the observations.

Measures of variability are numbers that indicate the spread or scatter of observations; they show the extent to which individual values in a data set differ from one another and, hence, differ from their central location.

A student scores 89, 75, 94, and 88 on four exams during the semester and 97 on the final exam. If the final is weighted double and the four others weighted equally, the student's final average would be 90.

The 10th percentile of a set of measurements is the value that exceeds 90% of the measurements and is less than the remaining 10% of the measurements.

Suppose the standard deviation for a given sample is known to be 12. If each data value in the sample is multiplied by 3, the standard deviation will be 36.

One of the advantages of the standard deviation over the variance as a measure of variability is that the standard deviation is measured in the original units.

The standard deviation is always smaller than the variance.

If two data sets have the same range, which of the following characteristics do these data sets also share?

The mean is a measure of the middle centre of a distribution.

Which of the following represents a disadvantage of using the sample range to measure dispersion?

Which of the following statements about the mean is NOT always correct?

Which of the following is the most frequently used measure of variation?

Which of the following statements describes the variance of a data set?

Cracks in Bar The following data represent the number of small cracks per bar for a sample of eight steel bars: 4, 6, 10, 1, 3, 1, 25, and 8. -Refer to Cracks in Bar statement. Which, if any, of the observations appear to be outliers? Justify your answer.

A sample of 2500 vehicles in Minnesota showed the following statistics related to the number of accidents per month: and Based on these data, we can conclude that the distribution of accidents is skewed.

A sample of n = 10 measurements consists of the following values: 15, 12, 13, 16, 11, 12, 14, 15, 11, and 13. a. Can you use Tchebysheff's Theorem to describe this data set? Why or why not? b. Can you use the Empirical Rule to describe this data set? Why or why not?

Suppose that a particular statistical population can be described, at least roughly, by the normal curve. Which of the following can we use to estimate the percentages of all population values that lie within specified numbers of standard deviations from the mean?

In a histogram, what may be said of the proportion of the total area that must be to the right of the mean?

Describing Data With Graphs

Describing Bivariate Data

A: probability and Probability Distributions

B: probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Estimation

A: large-Sample Tests of Hypotheses

B: large-Sample Tests of Hypotheses

A: Inference From Small Samples

B: Inference From Small Samples

A: The Analysis of Variance

B: The Analysis of Variance

A: linear Regression and Correlation

B: linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

A:nonparametric Statistics

B:nonparametric Statistics

Filters

Exam 2: Describing Data With Numerical Measures

The value of the mean times the number of observations equals the sum of all of the observations.

Measures of variability are numbers that indicate the spread or scatter of observations; they show the extent to which individual values in a data set differ from one another and, hence, differ from their central location.

A student scores 89, 75, 94, and 88 on four exams during the semester and 97 on the final exam. If the final is weighted double and the four others weighted equally, the student's final average would be 90.

The 10th percentile of a set of measurements is the value that exceeds 90% of the measurements and is less than the remaining 10% of the measurements.

Suppose the standard deviation for a given sample is known to be 12. If each data value in the sample is multiplied by 3, the standard deviation will be 36.

One of the advantages of the standard deviation over the variance as a measure of variability is that the standard deviation is measured in the original units.

The standard deviation is always smaller than the variance.

If two data sets have the same range, which of the following characteristics do these data sets also share?

The mean is a measure of the middle centre of a distribution.

Which of the following represents a disadvantage of using the sample range to measure dispersion?

Which of the following statements about the mean is NOT always correct?

Which of the following is the most frequently used measure of variation?

Which of the following statements describes the variance of a data set?

Cracks in Bar The following data represent the number of small cracks per bar for a sample of eight steel bars: 4, 6, 10, 1, 3, 1, 25, and 8. -Refer to Cracks in Bar statement. Which, if any, of the observations appear to be outliers? Justify your answer.

A sample of 2500 vehicles in Minnesota showed the following statistics related to the number of accidents per month: and Based on these data, we can conclude that the distribution of accidents is skewed.

A sample of n = 10 measurements consists of the following values: 15, 12, 13, 16, 11, 12, 14, 15, 11, and 13. a. Can you use Tchebysheff's Theorem to describe this data set? Why or why not? b. Can you use the Empirical Rule to describe this data set? Why or why not?

Suppose that a particular statistical population can be described, at least roughly, by the normal curve. Which of the following can we use to estimate the percentages of all population values that lie within specified numbers of standard deviations from the mean?

In a histogram, what may be said of the proportion of the total area that must be to the right of the mean?

Describing Data With Graphs

Describing Bivariate Data

A: probability and Probability Distributions

B: probability and Probability Distributions

Several Useful Discrete Distributions

The Normal Probability Distribution

Sampling Distributions

Large-Sample Estimation

A: large-Sample Tests of Hypotheses

B: large-Sample Tests of Hypotheses

A: Inference From Small Samples

B: Inference From Small Samples

A: The Analysis of Variance

B: The Analysis of Variance

A: linear Regression and Correlation

B: linear Regression and Correlation

Multiple Regression Analysis

Analysis of Categorical Data

A:nonparametric Statistics

B:nonparametric Statistics

Filters