Question 1

You are given a sample of 8 measurements: 13, 11, 15, 16, 14, 14, 13, and 15. Calculate the sample mean.

Accepted Answer

The answer of You are given a sample of 8...

Question 2

According to Tchebysheff's Theorem, at least 96% of observations should fall within five standard deviations of the mean.

Accepted Answer

A) True 
 B)False

Question 3

Jessica has been keeping track of what she spends to eat out. Last week's expenditures for meals eaten out were $15.69, $15.95, $16.19, $20.91, $17.49, $24.53, and $17.66. The mean amount Jessica spends on meals is $18.35.

Accepted Answer

A) True 
 B)False

Question 4

Optometrist Customers
The following values denote the number of customers handled by an optometrist during a random sample of four periods of one hour each: 4, 6, 2, and 5.
-Refer to the Optometrist Customers statement. Find the range R.

Accepted Answer

The answer of Optometrist Customers
The following values denote the number...

Question 5

In a histogram, what may one conclude about the proportion of the total area that must be to the left of the median?

Accepted Answer

A)  It is exactly 0.50. 
B)  It is less than 0.50 if the distribution is skewed to the left. 
C)  It is more than 0.50 if the distribution is skewed to the right. 
D)  It is between 0.25 and 0.75 if the distribution is symmetric. 
A)  It is exactly 0.50. 
B)  It is less than 0.50 if the distribution is skewed to the left. 
C)  It is more than 0.50 if the distribution is skewed to the right. 
D)  It is between 0.25 and 0.75 if the distribution is symmetric.

Question 6

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. Find the standard deviation for the number of small cracks per bar.

Accepted Answer

The answer of Cracks in Bar
The following data represent the...

Question 7

The value of the standard deviation may be either positive or negative, while the value of the variance will always be positive or zero.

Accepted Answer

A) True 
 B)False

Question 8

Frequency Table
Suppose you are given the following frequency table of ratings from 0 to 8:   Assume that the sample mean and the sample standard deviation are 0.66 and 1.387, respectively.
-Refer to the Frequency Table. What fraction of the x-values fall within two standard deviations of the mean? Within three standard deviations of the mean?

Accepted Answer

0.95 of the x values fall with

Question 9

Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as   .

Accepted Answer

A) True 
 B)False

Question 10

Motor Skills of Children
The times required for 10 children to learn a particular motor skill were recorded as 9, 15, 23, 20, 16, 15, 24, 18, 10, and 20 minutes.
-Refer to Motor Skills of Children statement. Find the mean time to learn this task.

Accepted Answer

The answer of Motor Skills of Children
The times required for...

Question 11

The distribution of credit card balances for customers is highly skewed to the right, with a mean of $1200 and a standard deviation of $150. Based on this information, approximately 68% of the customers will have credit card balances between $1050 and $1350.

Accepted Answer

A) True 
 B)False

Question 12

Aptitude Tests
Twenty-eight applicants interested in working in community services took an examination designed to measure their aptitude for social work. A stem-and-leaf plot of the 28 scores appears below, in which the first column is the count per "branch," the second column is the stem value, and the remaining digits are the leaves.
Count Stems Leaves
1 4 6
1 5 9
4 6 3688
6 7 026799
9 8 145667788
7 9 1234788
-Refer to Aptitude Tests table. Find the outer fences.

Accepted Answer

Q₁ - 3(IQR) = 70.5 -

Question 13

The lengths of screws produced by a machine are normally distributed, with a mean of 3 cm and a standard deviation of 0.2 cm. What can we conclude from this?

Accepted Answer

A)  Approximately 68% of all screws have lengths between 2.8 and 3.2 cm. 
B)  Approximately 95% of all screws have lengths between 2.8 and 3.2 cm. 
C)  Just about all screws have lengths between 2.8 and 3.2 cm. 
D)  Just about all screws have lengths between 2.9 and 3.1 cm. 
A)  Approximately 68% of all screws have lengths between 2.8 and 3.2 cm. 
B)  Approximately 95% of all screws have lengths between 2.8 and 3.2 cm. 
C)  Just about all screws have lengths between 2.8 and 3.2 cm. 
D)  Just about all screws have lengths between 2.9 and 3.1 cm.

Question 14

According to Tchebysheff's Theorem, what is the percentage of measurements in a data set that will fall within three standard deviations of the mean?

Accepted Answer

A)  16% 
B)  at least 68% 
C)  75% 
D)  at least 89% 
A)  16% 
B)  at least 68% 
C)  75% 
D)  at least 89%

Question 15

A sample of 50 values produced the following summary statistics:       and   Based on this information, what are the left and right ends, respectively, of the box plot using whiskers?

Accepted Answer

A)  5.3 and 32.0 
B)  10 and 14.6 
C)  10 and 16.7 
D)  14.6 and 16.7 
A)  5.3 and 32.0 
B)  10 and 14.6 
C)  10 and 16.7 
D)  14.6 and 16.7

Question 16

The following data represent scores on a 15-point aptitude test: 8, 10, 15, 12, 14, and 13. Subtract 5 from every observation and compute the sample mean for both the original data and the new data. What effect, if any, does subtracting 5 from every observation have on the sample mean?

Accepted Answer

@#IMG-DLM& = 12, and @#IMG-DLM& = 7. The

Question 17

Student Ratings
Thirty-three students were asked to rate themselves on whether they were outgoing or not, using this five-point scale: 1 = extremely extroverted, 2 = extroverted, 3 = neither extroverted nor introverted, 4 = introverted, or 5 = extremely introverted. The results are shown in the table below:  
-Refer to Student Ratings table. Calculate the sample mean.

Accepted Answer

The answer of Student Ratings
Thirty-three students were asked to rate...

Question 18

Aptitude Tests
Twenty-eight applicants interested in working in community services took an examination designed to measure their aptitude for social work. A stem-and-leaf plot of the 28 scores appears below, in which the first column is the count per "branch," the second column is the stem value, and the remaining digits are the leaves.
Count Stems Leaves
1 4 6
1 5 9
4 6 3688
6 7 026799
9 8 145667788
7 9 1234788
-Refer to Aptitude Tests table. Find the inner fences.

Accepted Answer

Q₁ - 1.5(IQR) = 70.5

Question 19

The sample variance calculated with a divisor of n gives a better estimate of the population variance, $\sigma$2, than does the sample variance, s2, with a divisor of n - 1.

Accepted Answer

A) True 
 B)False

Question 20

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

You are given a sample of 8 measurements: 13, 11, 15, 16, 14, 14, 13, and 15. Calculate the sample mean.

According to Tchebysheff's Theorem, at least 96% of observations should fall within five standard deviations of the mean.

Jessica has been keeping track of what she spends to eat out. Last week's expenditures for meals eaten out were $15.69, $15.95, $16.19, $20.91, $17.49, $24.53, and $17.66. The mean amount Jessica spends on meals is $18.35.

Optometrist Customers The following values denote the number of customers handled by an optometrist during a random sample of four periods of one hour each: 4, 6, 2, and 5. -Refer to the Optometrist Customers statement. Find the range R.

In a histogram, what may one conclude about the proportion of the total area that must be to the left of the median?

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. Find the standard deviation for the number of small cracks per bar.

The value of the standard deviation may be either positive or negative, while the value of the variance will always be positive or zero.

Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as $Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as .$ .

Motor Skills of Children The times required for 10 children to learn a particular motor skill were recorded as 9, 15, 23, 20, 16, 15, 24, 18, 10, and 20 minutes. -Refer to Motor Skills of Children statement. Find the mean time to learn this task.

The distribution of credit card balances for customers is highly skewed to the right, with a mean of $1200 and a standard deviation of $150. Based on this information, approximately 68% of the customers will have credit card balances between $1050 and $1350.

The lengths of screws produced by a machine are normally distributed, with a mean of 3 cm and a standard deviation of 0.2 cm. What can we conclude from this?

According to Tchebysheff's Theorem, what is the percentage of measurements in a data set that will fall within three standard deviations of the mean?

A sample of 50 values produced the following summary statistics: and Based on this information, what are the left and right ends, respectively, of the box plot using whiskers?

The following data represent scores on a 15-point aptitude test: 8, 10, 15, 12, 14, and 13. Subtract 5 from every observation and compute the sample mean for both the original data and the new data. What effect, if any, does subtracting 5 from every observation have on the sample mean?

The sample variance calculated with a divisor of n gives a better estimate of the population variance, $\sigma$ ², than does the sample variance, s², with a divisor of n - 1.

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?

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

You are given a sample of 8 measurements: 13, 11, 15, 16, 14, 14, 13, and 15. Calculate the sample mean.

According to Tchebysheff's Theorem, at least 96% of observations should fall within five standard deviations of the mean.

Jessica has been keeping track of what she spends to eat out. Last week's expenditures for meals eaten out were $15.69, $15.95, $16.19, $20.91, $17.49, $24.53, and $17.66. The mean amount Jessica spends on meals is $18.35.

Optometrist Customers The following values denote the number of customers handled by an optometrist during a random sample of four periods of one hour each: 4, 6, 2, and 5. -Refer to the Optometrist Customers statement. Find the range R.

In a histogram, what may one conclude about the proportion of the total area that must be to the left of the median?

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. Find the standard deviation for the number of small cracks per bar.

The value of the standard deviation may be either positive or negative, while the value of the variance will always be positive or zero.

Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as .

Motor Skills of Children The times required for 10 children to learn a particular motor skill were recorded as 9, 15, 23, 20, 16, 15, 24, 18, 10, and 20 minutes. -Refer to Motor Skills of Children statement. Find the mean time to learn this task.

The distribution of credit card balances for customers is highly skewed to the right, with a mean of $1200 and a standard deviation of $150. Based on this information, approximately 68% of the customers will have credit card balances between $1050 and $1350.

The lengths of screws produced by a machine are normally distributed, with a mean of 3 cm and a standard deviation of 0.2 cm. What can we conclude from this?

According to Tchebysheff's Theorem, what is the percentage of measurements in a data set that will fall within three standard deviations of the mean?

A sample of 50 values produced the following summary statistics: and Based on this information, what are the left and right ends, respectively, of the box plot using whiskers?

The following data represent scores on a 15-point aptitude test: 8, 10, 15, 12, 14, and 13. Subtract 5 from every observation and compute the sample mean for both the original data and the new data. What effect, if any, does subtracting 5 from every observation have on the sample mean?

The sample variance calculated with a divisor of n gives a better estimate of the population variance, σ\sigmaσ 2, than does the sample variance, s2, with a divisor of n - 1.

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?

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

Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as $Tchebysheff's Theorem gives a lower bound to the fraction of measurements to be found in an interval constructed as .$ .

The sample variance calculated with a divisor of n gives a better estimate of the population variance, $\sigma$ ², than does the sample variance, s², with a divisor of n - 1.