Question 1

For one coastal state, there is a high correlation between ice cream sales and number of people swimming in the ocean. Suggest a possible lurking variable and explain what is meant by the term lurking variable.

Accepted Answer

The answer of  For one coastal state, there is...

Question 2

A value of r really close to -1 means that the linear association ______.

Accepted Answer

A)  is very weak 
B)  is very strong 
C)  cannot be determined 
D)  None of these

Question 3

Consider the data set Calculate the (a) sample means (b) S_xx , S_xy , S_yy (c) sample correlation coefficient.

Accepted Answer

The answer of Consider the data set
  
Calculate the
(a)...

Question 4

Consider the data set Calculate the (a) sample means (b)S_xx , S_xy , S_yy (c) sample correlation coefficient.

Accepted Answer

The answer of Consider the data set
  Calculate the
(a)...

Question 5

If all (x, y) values lie exactly on a straight line with a ______ slope, then r = +1.

Accepted Answer

The answer of If all (x, y) values lie exactly...

Question 6

A scientist in a center for disease control observes that the number of bacteria in a culture and air pollution in the city rise with time. Is there exists a lurking variable in this case?

Accepted Answer

The answer of A scientist in a center for disease...

Question 7

Consider the data set
  Find the sample correlation coefficient using the formula 
  
.

Accepted Answer

The answer of Consider the data set
  Find the...

Question 8

Consider the data set
   
A) Complete the table.
  Use the formula 
  
 to calculate the sample correlation. Round your answer to three decimal places.

Accepted Answer

The answer of Consider the data set
   
A)...

Question 9

Calculations from a data set of n = 36 pairs of (x, y) values have provided the following results.
  
Obtain the correlation coefficient.

Accepted Answer

The answer of Calculations from a data set of n...

Question 10

For the data set, compute the least squares estimates.
  
A)   
B)

Accepted Answer

The answer of For the data set, compute the least...

Question 11

A line is determined by two constants. One of these constants is the ______, that is, the amount that y increases whenever x is increased by one unit.

Accepted Answer

The answer of A line is determined by two constants....

Question 12

The sign of the correlation coefficient r, indicates the weakness of a linear relation.

Accepted Answer

A) True 
 B)False

Question 13

Consider the line

A) What is its intercept?
B) What is its slope?

Accepted Answer

The answer of Consider the line

A) What...

Question 14

A line is determined by two constants. One of these constants is the ______, that is, its height above the origin.

Accepted Answer

The answer of A line is determined by two constants....

Question 15

In a group of 180 college students, 43 are science majors, 66 are freshmen, and 31 are both. Based on these data, complete the following two-way frequency table.

Accepted Answer

The answer of In a group of 180 college students,...

Question 16

Suppose from a data set of distance measurements in yards and time measurements in hours, the value of r is found to be 0.82. What would the value of r be if the distances were measured in feet and time in minutes.

Accepted Answer

A)  -.82 
B)  .82 
C)  .27 
D)  .01

Question 17

Estimate the correlation coefficient of the figure below.

Accepted Answer

A)  .5 
B)  .1 
C)  -.5 
D)  -.8

Question 18

Is the correlation in the figure about 
(a) .2, (b) -.4, (c) .4, (d) .8, or (e) -.9?

Accepted Answer

The answer of Is the correlation in the figure about...

Question 19

If the pattern of (x, y) values is a band that runs from ______ left to ______ right, then 
r > 0.

Accepted Answer

The answer of If the pattern of (x, y) values...

Question 20

Find the scatter diagram that corresponds to the correlation coefficient r = -.8.

Accepted Answer

A) 
 
B) 
 
C) 
 
D)

Exam 3: Descriptive Study of Bivariate Data

For one coastal state, there is a high correlation between ice cream sales and number of people swimming in the ocean. Suggest a possible lurking variable and explain what is meant by the term lurking variable.

A value of r really close to -1 means that the linear association ______.

Consider the data set Calculate the (a) sample means (b) S_xx , S_xy , S_yy (c) sample correlation coefficient.

Consider the data set Calculate the (a) sample means (b)S_xx , S_xy , S_yy (c) sample correlation coefficient.

If all (x, y) values lie exactly on a straight line with a ______ slope, then r = +1.

A scientist in a center for disease control observes that the number of bacteria in a culture and air pollution in the city rise with time. Is there exists a lurking variable in this case?

Consider the data set Find the sample correlation coefficient using the formula .

Consider the data set A) Complete the table. Use the formula to calculate the sample correlation. Round your answer to three decimal places.

Calculations from a data set of n = 36 pairs of (x, y) values have provided the following results. Obtain the correlation coefficient.

For the data set, compute the least squares estimates. A) B)

A line is determined by two constants. One of these constants is the ______, that is, the amount that y increases whenever x is increased by one unit.

The sign of the correlation coefficient r, indicates the weakness of a linear relation.

Consider the line A) What is its intercept? B) What is its slope?

A line is determined by two constants. One of these constants is the ______, that is, its height above the origin.

In a group of 180 college students, 43 are science majors, 66 are freshmen, and 31 are both. Based on these data, complete the following two-way frequency table.

Suppose from a data set of distance measurements in yards and time measurements in hours, the value of r is found to be 0.82. What would the value of r be if the distances were measured in feet and time in minutes.

Estimate the correlation coefficient of the figure below.

Is the correlation in the figure about (a) .2, (b) -.4, (c) .4, (d) .8, or (e) -.9?

If the pattern of (x, y) values is a band that runs from left to right, then r > 0.

Find the scatter diagram that corresponds to the correlation coefficient r = -.8.

Exam 3: Descriptive Study of Bivariate Data

For one coastal state, there is a high correlation between ice cream sales and number of people swimming in the ocean. Suggest a possible lurking variable and explain what is meant by the term lurking variable.

A value of r really close to -1 means that the linear association ______.

Consider the data set Calculate the (a) sample means (b) Sxx , Sxy , Syy (c) sample correlation coefficient.

Consider the data set Calculate the (a) sample means (b)Sxx , Sxy , Syy (c) sample correlation coefficient.

If all (x, y) values lie exactly on a straight line with a ______ slope, then r = +1.

A scientist in a center for disease control observes that the number of bacteria in a culture and air pollution in the city rise with time. Is there exists a lurking variable in this case?

Consider the data set Find the sample correlation coefficient using the formula .

Consider the data set A) Complete the table. Use the formula to calculate the sample correlation. Round your answer to three decimal places.

Calculations from a data set of n = 36 pairs of (x, y) values have provided the following results. Obtain the correlation coefficient.

For the data set, compute the least squares estimates. A) B)

A line is determined by two constants. One of these constants is the ______, that is, the amount that y increases whenever x is increased by one unit.

The sign of the correlation coefficient r, indicates the weakness of a linear relation.

Consider the line A) What is its intercept? B) What is its slope?

A line is determined by two constants. One of these constants is the ______, that is, its height above the origin.

In a group of 180 college students, 43 are science majors, 66 are freshmen, and 31 are both. Based on these data, complete the following two-way frequency table.

Suppose from a data set of distance measurements in yards and time measurements in hours, the value of r is found to be 0.82. What would the value of r be if the distances were measured in feet and time in minutes.

Estimate the correlation coefficient of the figure below.

Is the correlation in the figure about (a) .2, (b) -.4, (c) .4, (d) .8, or (e) -.9?

If the pattern of (x, y) values is a band that runs from ______ left to ______ right, then r > 0.

Find the scatter diagram that corresponds to the correlation coefficient r = -.8.

Consider the data set Calculate the (a) sample means (b) S_xx , S_xy , S_yy (c) sample correlation coefficient.

Consider the data set Calculate the (a) sample means (b)S_xx , S_xy , S_yy (c) sample correlation coefficient.

If the pattern of (x, y) values is a band that runs from left to right, then r > 0.