Question 1

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression to predict the average attendance from the number of games won has an 
= 31.4%.The residuals plot indicated that a linear model is appropriate.What is the correlation between the average attendance and the number of games won.

Accepted Answer

The answer of The relationship between the number of games...

Question 2

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars)from length (in feet)has an 
= 19.00%.What would you predict about the price of the yacht whose length was one standard deviation above the mean?

Accepted Answer

The answer of A random sample of 150 yachts sold...

Question 3

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression to predict the average attendance from the number of games won has an r = 0.79.Interpret this statistic.

Accepted Answer

The correlation coefficient r = 0.79 indicates a positive, fairly strong linear relationship. The coefficient of determination, r^2, is 0.79^2 = 0.6241, meaning 62.41% of the variation in average attendance is explained by the number of games won.

Question 4

A golf ball is dropped from 15 different heights (in cm)and the height of the bounce is recorded (in cm. )The regression analysis gives the model 
= 0.4 + 0.72 drop.A golf ball dropped from 64 cm bounced 1 cm less than expected.How high did it bounce?

Accepted Answer

The answer of A golf ball is dropped from 15...

Question 5

The relationship between the selling price (in dollars)of used Ford Escorts and their age (in years)is analyzed.A regression analysis to predict the price from the age gives the model 
= 14,210 - 1,348 age.You want to sell a 17 year old Escort.Use the model to determine an appropriate price.Explain any problems.

Accepted Answer

The predicted price using the regression model is 14,210 - 1,348(17) = -8,706. However, this negative value does not make sense as a selling price for a used car. Also, the model may not give meaningful prices for Escorts that are this old, especially if there are not many data points for Escorts of this age in the dataset. Therefore, the best choice is E, which acknowledges both of these issues.

Question 6

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an 
= 85.8%.Why doesn't the model explain 100% of the variation in the price of an Escort?

Accepted Answer

Linear regression models only account for the variation explained by the independent variable(s) included in the model. Other factors, such as mileage, options, and condition of the car, can also affect the price and were not included in the model. Therefore, the model does not explain all of the variation in price.

Question 7

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression to predict the average attendance from the number of games won has an 
= 30.4%.The residuals plot indicated that a linear model is appropriate.Write a sentence summarizing what 
Says about this regression.

Accepted Answer

The coefficient of determination (R-squared value) of 0.304 indicates that the number of games won explains 30.4% of the variation in average attendance. Therefore, D is the best choice.

Question 8

A random sample of records of electricity usage of homes in the month of July gives the amount of electricity used and size (in square feet)of 135 homes.A regression was done to predict the amount of electricity used (in kilowatt-hours)from size.The residuals plot indicated that a linear model is appropriate.The model is 
= 1,240 + 0.5 size.How much electricity would you predict would be used in a house that is 2,372 square feet?

Accepted Answer

Using the given model 11ea7dab_38f2_14e5_b67a_ed9b244ee79d_TB3448_11_TB3448_11= 1,240 + 0.5 size, we can plug in the given size of the house (2,372 square feet):
11ea7dab_38f2_14e5_b67a_ed9b244ee79d_TB3448_11_TB3448_11= 1,240 + 0.5 (2,372) = 1,240 + 1,186 = 2,426 kilowatt-hours.

Therefore, the best choice is D, which represents the predicted amount of electricity that would be used in a house that is 2,372 square feet.

Question 9

A random sample of records of electricity usage of homes gives the amount of electricity used and size (in square feet)of 135 homes.A regression to predict the amount of electricity used (in kilowatt-hours)from size has an R-squared of 71.3%.The residuals plot indicated that a linear model is appropriate.Write a sentence summarizing what 
Says about this regression.

Accepted Answer

The R-squared value of 71.3% indicates that 71.3% of the variation in electricity usage can be explained by the variation in size of homes. Therefore, size differences have a strong relationship with electricity usage.

Question 10

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an 
= 88.2%.Describe the relationship

Accepted Answer

The answer of Using advertised prices for used Ford Escorts...

Question 11

The relationship between the number of games won during one season by an NHL team and the average attendance at their home games is analyzed.A regression analysis to predict the average attendance from the number of games won gives the model = -2,100 + 187 wins.Predict the average attendance of a team with 400 wins.Explain any possible problems with this prediction.

Accepted Answer

The answer of The relationship between the number of games...

Question 12

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars)from length (in metres)has an 
= 15.2%.What would you predict about the price of the yacht whose length was two standard deviations below the mean?

Accepted Answer

The answer of A random sample of 150 yachts sold...

Question 13

A golf ball is dropped from 15 different heights (in cm)and the height of the bounce is recorded (in cm. )The regression analysis gives the model 
= -0.1 + 0.70 drop.Predict the height of the bounce if dropped from 64 cm.

Accepted Answer

The answer of A golf ball is dropped from 15...

Question 14

A golf ball is dropped from 15 different heights (in cm)and the height of the bounce is recorded (in cm. )The regression analysis gives the model 
= 0.3 + 0.74 drop.A golf ball dropped from 61 cm bounced 46.44 cm.What is the residual for this bounce height.?

Accepted Answer

The answer of A golf ball is dropped from 15...

Question 15

A random sample of records of electricity usage of homes in the month of July gives the amount of electricity used and size (in square feet)of 135 homes.A regression was done to predict the amount of electricity used (in kilowatt-hours)from size.The residuals plot indicated that a linear model is appropriate.The model is 
= 1,287 + 0.3 size.The people in a house that is 2,347 square feet used 500 kilowatt-hours less than expected.How much did they use?

Accepted Answer

The answer of A random sample of records of electricity...

Question 16

A random sample of records of electricity usage of homes in the month of July gives the amount of electricity used and size (in square feet)of 135 homes.A regression was done to predict the amount of electricity used (in kilowatt-hours)from size.The residuals plot indicated that a linear model is appropriate.The model is 
= 1,218 + 0.3 size.What would a negative residual mean for people living in a house that is 2,495 square feet?

Accepted Answer

A negative residual means that the actual amount of electricity used is less than what would be predicted by the model. Therefore, people living in a house that is 2,495 square feet are using less electricity than expected.

Question 17

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression analysis to predict the average attendance from the number of games won gives the model = -2,100 + 193 wins.Predict the average attendance of a team with 58 wins.

Accepted Answer

The answer of The relationship between the number of games...

Question 18

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an 
= 87.7%.Write a sentence summarizing what 
Says about this regression.

Accepted Answer

The coefficient of determination (R-squared) measures the proportion of variation in the dependent variable (price) that is explained by the independent variable (age). In this case, R-squared is 0.877, which means that 87.7% of the variation in price can be explained by the age of the car.

Question 19

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars)from length (in metres)has an 
= 18.3%.What is correlation between length and price?

Accepted Answer

The answer of A random sample of 150 yachts sold...

Question 20

The relationship between the selling price (in dollars)of used Ford Escorts and their age (in years)is analyzed.A regression analysis to predict the price from the age gives the model 
= 14,458 - 1,472age.Predict the price of an Escort that is 8 years old.

Accepted Answer

The answer of The relationship between the selling price (in...

Quiz 7: Linear Regression

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars) from length (in feet) has an = 19.00%.What would you predict about the price of the yacht whose length was one standard deviation above the mean?

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression to predict the average attendance from the number of games won has an r = 0.79.Interpret this statistic.

A golf ball is dropped from 15 different heights (in cm) and the height of the bounce is recorded (in cm. ) The regression analysis gives the model = 0.4 + 0.72 drop.A golf ball dropped from 64 cm bounced 1 cm less than expected.How high did it bounce?

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an = 85.8%.Why doesn't the model explain 100% of the variation in the price of an Escort?

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an = 88.2%.Describe the relationship

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars) from length (in metres) has an = 15.2%.What would you predict about the price of the yacht whose length was two standard deviations below the mean?

A golf ball is dropped from 15 different heights (in cm) and the height of the bounce is recorded (in cm. ) The regression analysis gives the model = -0.1 + 0.70 drop.Predict the height of the bounce if dropped from 64 cm.

A golf ball is dropped from 15 different heights (in cm) and the height of the bounce is recorded (in cm. ) The regression analysis gives the model = 0.3 + 0.74 drop.A golf ball dropped from 61 cm bounced 46.44 cm.What is the residual for this bounce height.?

The relationship between the number of games won by an NHL team and the average attendance at their home games is analyzed.A regression analysis to predict the average attendance from the number of games won gives the model = -2,100 + 193 wins.Predict the average attendance of a team with 58 wins.

Using advertised prices for used Ford Escorts a linear model for the relationship between a car's age and its price is found.The regression has an = 87.7%.Write a sentence summarizing what Says about this regression.

A random sample of 150 yachts sold in Canada last year was taken.A regression to predict the price (in thousands of dollars) from length (in metres) has an = 18.3%.What is correlation between length and price?

The relationship between the selling price (in dollars) of used Ford Escorts and their age (in years) is analyzed.A regression analysis to predict the price from the age gives the model = 14,458 - 1,472age.Predict the price of an Escort that is 8 years old.