Question 1

The median,the second quartile,and the 50th percentile are all the same.

Accepted Answer

A) True 
 B)False

Question 2

Although the range measures the total spread of the data,the interquartile range (IQR)measures only the spread of the middle 50% of the data.

Accepted Answer

A) True 
 B)False

Question 3

The interquartile range is the average of the first and third quartiles.

Accepted Answer

A) True 
 B)False

Question 4

For the following scatter plot,what would be your best estimate of the correlation coefficient?

Accepted Answer

A) -0.8 
B) -1.0 
C) 0)0 
D) -0.3

Question 5

Calculate the location of the 25^th,50^th,and 75^th percentile and their values,using the following data: 0 0 5 7 8 9 12 14 22 33

Accepted Answer

The answer of Calculate the location of the 25^th,50^th,and 75^th...

Question 6

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Production records for an automobile manufacturer show the following figures for production per shift (maximum production is 720 cars per shift):
 
-Find the median.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 7

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
An investment councilor recently reviewed the account activity of a sample of 10 of his clients and calculated the average number of stock trades per month over the past year for each client.He obtained the following data values: 10.2,2.5,11.4,3.2,1.1,3.4,8.4,9.7,11.2,and 2.4
-Calculate the average number of trades per month for these 10 clients.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 8

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following (x,y)sample data: (24,24),(19,33),(21,31),(10,36),(22,30),(13,36),(21,32),(23,26),(20,26),and (21,31). -Calculate the variances and and the covariance s_xy.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 9

Give an example to illustrate that the median should not always be preferred to the mean when the population or sample is skewed.

Accepted Answer

The answer of Give an example to illustrate that the...

Question 10

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A set of data is mounded,with a mean of 500 and a variance of 576.
-Approximately what proportion of the observations is between 452 and 548?

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 11

What would you conclude if a sample correlation coefficient is equal to -1.00?

Accepted Answer

A) All the data points must fall exactly on a straight line with a positive slope. 
B) All the data points must fall exactly on a straight line with a negative slope. 
C) Most of the data points must fall exactly on a straight line with a positive slope 
D) Most of the data points must fall exactly on a horizontal straight line

Question 12

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
The following data represent a sample of 10 scores on a statistics quiz: 16,16,16,16,16,18,18,20,20,and 20.
-The median score is:

Accepted Answer

A) 16 
B) 17 
C) 18 
D) 19

Question 13

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
A small accounting office is trying to determine its staffing needs for the coming tax season.The manager has collected the following data: 46,27,79,57,99,75,48,89,and 85.These values represent the number of returns the office completed each year over the entire nine years it has been doing tax returns.
-For this data,what is the variance of the number of tax returns completed each year?

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 14

A bored carpenter counts the actual number of nails in 10 boxes of nails and records his findings as: 230,235,302,287,312,323,265,319,342,and 298.What can we say about the shape of the distribution of the number of nails?

Accepted Answer

A) symmetric 
B) skewed to the right 
C) approximately bell-shaped 
D) skewed to the left

Question 15

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
Consider the following (x,y)sample data: (53,37),(34,26),(10,29),(63,55),(28,36),(58,48),(28,41),(50,42),(39,21),and (35,46).
-Calculate the correlation coefficient sample data.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 16

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION:
In a recent survey,200 top executives were asked how many hours they spend each year in community service.The data are presented below.
 
-Calculate the quantities  
,  
  
,and  
  
.

Accepted Answer

The answer of THE NEXT QUESTIONS ARE BASED ON THE...

Question 17

Which of the following statements is true about the correlation coefficient and covariance?

Accepted Answer

A) The covariance is the preferred measure of the relationship between two variables since it is generally larger than the correlation coefficient. 
B) The correlation coefficient is a preferred measure of the relationship between two variables since its calculation is easier than the covariance. 
C) The covariance is a standardized measure of the linear relationship between two variables. 
D) The covariance and corresponding correlation coefficient are represented by different signs,one is negative while the other is positive and vice versa.

Question 18

The five-number summary refers to the five descriptive measures: minimum,mean,median,mode,and maximum;therefore it is sometimes known as the five-m summary.

Accepted Answer

A) True 
 B)False

Question 19

A z-score is a standardized value that indicates the number of standard deviations a value is from the:

Accepted Answer

A) mean. 
B) mode. 
C) median. 
D) frequency.

Question 20

Based on the values of the mean and median in the previous two questions,are the measurements symmetric or skewed? Why?

Accepted Answer

The answer of Based on the values of the mean...

Exam 2: Describing Data: Numerical

The median,the second quartile,and the 50th percentile are all the same.

Although the range measures the total spread of the data,the interquartile range (IQR)measures only the spread of the middle 50% of the data.

The interquartile range is the average of the first and third quartiles.

For the following scatter plot,what would be your best estimate of the correlation coefficient?

Calculate the location of the 25th,50th,and 75th percentile and their values,using the following data: 0 0 5 7 8 9 12 14 22 33

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Production records for an automobile manufacturer show the following figures for production per shift (maximum production is 720 cars per shift): -Find the median.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following (x,y)sample data: (24,24),(19,33),(21,31),(10,36),(22,30),(13,36),(21,32),(23,26),(20,26),and (21,31). -Calculate the variances and and the covariance sxy.

Give an example to illustrate that the median should not always be preferred to the mean when the population or sample is skewed.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: A set of data is mounded,with a mean of 500 and a variance of 576. -Approximately what proportion of the observations is between 452 and 548?

What would you conclude if a sample correlation coefficient is equal to -1.00?

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: The following data represent a sample of 10 scores on a statistics quiz: 16,16,16,16,16,18,18,20,20,and 20. -The median score is:

A bored carpenter counts the actual number of nails in 10 boxes of nails and records his findings as: 230,235,302,287,312,323,265,319,342,and 298.What can we say about the shape of the distribution of the number of nails?

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following (x,y)sample data: (53,37),(34,26),(10,29),(63,55),(28,36),(58,48),(28,41),(50,42),(39,21),and (35,46). -Calculate the correlation coefficient sample data.

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: In a recent survey,200 top executives were asked how many hours they spend each year in community service.The data are presented below. -Calculate the quantities , ,and .

Which of the following statements is true about the correlation coefficient and covariance?

The five-number summary refers to the five descriptive measures: minimum,mean,median,mode,and maximum;therefore it is sometimes known as the five-m summary.

A z-score is a standardized value that indicates the number of standard deviations a value is from the:

Based on the values of the mean and median in the previous two questions,are the measurements symmetric or skewed? Why?

Calculate the location of the 25^th,50^th,and 75^th percentile and their values,using the following data: 0 0 5 7 8 9 12 14 22 33

THE NEXT QUESTIONS ARE BASED ON THE FOLLOWING INFORMATION: Consider the following (x,y)sample data: (24,24),(19,33),(21,31),(10,36),(22,30),(13,36),(21,32),(23,26),(20,26),and (21,31). -Calculate the variances and and the covariance s_xy.