Exam 7: Linear Regression

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.

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.

Two different tests are designed to measure employee productivity and dexterity.Several employees are randomly selected and tested with these results.

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.

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 + 0.69 drop.Explain what the slope of the line says about the bounce height and the drop height of the ball.

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 = -0.2 + 0.75 drop.A golf ball dropped from 61 cm bounced a height whose residual is -1.8 cm.What is the 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.

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?

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?

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 price of yachts (y)and their length (x)is analyzed.The mean length was 41 metres with a standard deviation of 11.The mean price was $84,000 with a standard deviation of 14,000.The correlation between the price and the length was 0.41.

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 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 was dropped from 8 different heights.The drop height and the bounce height were recorded.

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.

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.