Question 1

The coefficient of variation is a measure of variability.

Accepted Answer

A) True 
 B)False

Question 2

Weights of Police Officers
The following data represent the weights in pounds of a sample of 25 police officers: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171.
-{Weights of Police Officers Narrative} Construct a frequency distribution for the data,using five class intervals,and the value 130 as the lower limit of the first class.

Accepted Answer

\[\begin{array} { | c | c | } 
\hline \t

Question 3

Test Scores
Suppose that an analysis of a set of test scores reveals that: QS1U1B11S1U1B0 = 45,QS1U1B12S1U1B0 = 85,QS1U1B13S1U1B0 = 105.
-{Test Scores Narrative} Calculate the interquartile range.What does this tell you about the data?

Accepted Answer

Interquartile range = Q<sub>3<

Question 4

$\sigma$ is a population parameter and $\bar { x }$ is a sample statistic.

Accepted Answer

A) True 
 B)False

Question 5

Pets Survey
A sample of 36 families were asked how many pets they owned.Their responses are summarized in the following table.
 $$\begin{array} { | l | l l l l l l | } 
\hline \text { Number of Pets } & 0 & 1 & 2 & 3 & 4 & 5 \
\hline \text { Number of Families } & 3 & 20 & 5 & 4 & 2 & 2 \
\hline
\end{array}$$
-{Pets Survey Narrative} Determine the mean,the median,and the mode of the number of pets owned per family.

Accepted Answer

@#LAT-DLM& = [(0 *3)+ (1 * 20)+ (2 * 5)+

Question 6

If the observations are in the millions,a standard deviation of 10 would be considered small.If the observations are all less than 50,a standard deviation of 10 would be considered large.

Accepted Answer

A) True 
 B)False

Question 7

Quartiles divide the observations in a data set into four parts with the same amount of data in each part.

Accepted Answer

A) True 
 B)False

Question 8

The ____________________ is calculated by finding the middle of the data set,when the data are ordered from smallest to largest.

Accepted Answer

The answer of The ____________________ is calculated by finding the...

Question 9

Weights of Teachers
The following data represent the weights in pounds of a sample of 25 teachers: 164,148,137,157,173,156,177,172,169,165,145,168,163,162,174,152,156,168,154,151,174,146,134,140,and 171.
-{Weights of Teachers Narrative} Which is a better measure of variability in the weights of the teachers,the standard deviation or the coefficient of variation?

Accepted Answer

Each has its own place.The sta

Question 10

The variance is more meaningful and easier to interpret compared to the standard deviation.

Accepted Answer

A) True 
 B)False

Question 11

The Empirical Rule states that the approximate percentage of measurements in a data set (providing that the data set has a bell shaped distribution)that fall within two standard deviations of their mean is approximately:

Accepted Answer

A)  68%. 
B)  75%. 
C)  95%. 
D)  99%. 
A)  68%. 
B)  75%. 
C)  95%. 
D)  99%.

Question 12

2-Year Investment
Suppose you make a 2-year investment of $5,000 and it grows by 100% to $10,000 during the first year.During the second year,however,the investment suffers a 50% loss,from $10,000 back to $5,000.
-{2-Year Investment Narrative} Compare the values of the arithmetic and geometric means.

Accepted Answer

Because there was no change in the value

Question 13

In a histogram,the proportion of the total area which must be to the right of the mean is:

Accepted Answer

A)  less than 0.50 if the distribution is negatively skewed. 
B)  exactly 0.50. 
C)  more than 0.50 if the distribution is positively skewed. 
D)  exactly 0.50 if the distribution is symmetric and unimodal. 
A)  less than 0.50 if the distribution is negatively skewed. 
B)  exactly 0.50. 
C)  more than 0.50 if the distribution is positively skewed. 
D)  exactly 0.50 if the distribution is symmetric and unimodal.

Question 14

Milk Demand
A supermarket has determined that daily demand for milk containers has an approximate bell shaped distribution,with a mean of 55 containers and a standard deviation of six containers.
-{Milk Demand Narrative} How often can we expect between 49 and 61 containers to be sold in a day? (Give a percentage. )

Accepted Answer

Approximat

Question 15

The 5-number summary consists of the smallest observation,the first quartile,the median,the third quartile,and the largest observation.

Accepted Answer

A) True 
 B)False

Question 16

The mean of fifty sales receipts is $65.75 and the standard deviation is $10.55.Using Chebysheff's Theorem,75% of the sales receipts were between $44.65 and $86.85.

Accepted Answer

A) True 
 B)False

Question 17

Ages of Volunteers
The following data represent the ages in years of a sample of 25 volunteers from a charitable organization: 31,43,56,23,49,42,33,61,44,28,48,38,44,35,40,64,52,42,47,39,53,27,36,35,and 20.
-{Ages of Volunteers Narrative} Compute the sample variance and sample standard deviation,and express the numbers in the appropriate units.

Accepted Answer

s² = 124.83

Question 18

The ____________________ is the least effective of all the measures of variability.

Accepted Answer

The answer of The ____________________ is the least effective of...

Question 19

The 10th ____________________ is the value for which 10% of the observations are less than that value.

Accepted Answer

The answer of The 10th ____________________ is the value for...

Question 20

Suppose that a firm's sales were $2,500,000 four years ago,and sales have grown annually by 25%,15%,-5%,and 10% since that time.What was the geometric mean growth rate in sales over the past four years?

Accepted Answer

If R_g is the geomet

Exam 4: A: Numerical Descriptive Techniques

The coefficient of variation is a measure of variability.

Test Scores Suppose that an analysis of a set of test scores reveals that: Q1 = 45,Q2 = 85,Q3 = 105. -{Test Scores Narrative} Calculate the interquartile range.What does this tell you about the data?

σ\sigmaσ is a population parameter and xˉ\bar { x }xˉ is a sample statistic.

Pets Survey A sample of 36 families were asked how many pets they owned.Their responses are summarized in the following table. Number of Pets 0 1 2 3 4 5 Number of Families 3 20 5 4 2 2 -{Pets Survey Narrative} Determine the mean,the median,and the mode of the number of pets owned per family.

If the observations are in the millions,a standard deviation of 10 would be considered small.If the observations are all less than 50,a standard deviation of 10 would be considered large.

Quartiles divide the observations in a data set into four parts with the same amount of data in each part.

The ____________________ is calculated by finding the middle of the data set,when the data are ordered from smallest to largest.

The variance is more meaningful and easier to interpret compared to the standard deviation.

The Empirical Rule states that the approximate percentage of measurements in a data set (providing that the data set has a bell shaped distribution)that fall within two standard deviations of their mean is approximately:

In a histogram,the proportion of the total area which must be to the right of the mean is:

The 5-number summary consists of the smallest observation,the first quartile,the median,the third quartile,and the largest observation.

The mean of fifty sales receipts is $65.75 and the standard deviation is $10.55.Using Chebysheff's Theorem,75% of the sales receipts were between $44.65 and $86.85.

The ____________________ is the least effective of all the measures of variability.

The 10th ____________________ is the value for which 10% of the observations are less than that value.

Suppose that a firm's sales were $2,500,000 four years ago,and sales have grown annually by 25%,15%,-5%,and 10% since that time.What was the geometric mean growth rate in sales over the past four years?

What Is Statistics

Graphical Descriptive Techniques I

Graphical Descriptive Techniques II

B: Numerical Descriptive Techniques

C: Numerical Descriptive Techniques

Data Collection and Sampling

Probability

A: Random Variables and Discrete Probability Distributions

B: Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Introduction to Estimation

Introduction to Hypothesis Testing

Inference About a Population

Inference About Comparing Two Populations

Analysis of Variance

Chi-Squared Tests

A: Simple Linear Regression and Correlation

B: Simple Linear Regression and Correlation

Multiple Regression

Model Building

Nonparametric Statistics

Time-Series Analysis and Forecasting

Statistical Process Control

Decision Analysis

Conclusion

Filters

Test Scores Suppose that an analysis of a set of test scores reveals that: Q₁ = 45,Q₂ = 85,Q₃ = 105. -{Test Scores Narrative} Calculate the interquartile range.What does this tell you about the data?

$\sigma$ is a population parameter and $\bar { x }$ is a sample statistic.