Exam 7: Linear Regression

A random sample of records of electricity usage of homes gives the amount of electricity used in July 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 = 1,248 + 0.6 size.Explain what the slope of the line says about the electricity usage and home size.

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 + 0.71 drop.Interpret the meaning of the y-intercept.

Ten Jeep Cherokee classified ads were selected.The age and prices of several used Ford Escorts are given in the table.

A random sample of records of electricity usage of homes gives the amount of electricity used in July 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.What units does the slope have?

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?

A biology student does a study to investigate the association between the amount of sunlight and the number of roses on a rosebush in one summer.(The Value is 58%)He claims that the amount of sunlight determines 58% of the number of roses on a rosebush in one summer.

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 psychologist does an experiment to determine whether an outgoing person can be identified by his or her handwriting.She claims that the Of 89% shows that this linear model is appropriate.

The relationship between the cost of a taxi ride (y)and the length of the ride (x)is analyzed.The mean length was 4.6 km with a standard deviation of 1.1.The mean cost was $8.70 with a standard deviation of 2.0.The correlation between the cost and the length was 0.81.

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.?

Ten students in a graduate program at Carleton University were randomly selected.Their grade point averages (GPAs)when they entered the program were between 11.5 and 12.0.The following data were obtained regarding their GPAs on entering the program versus their current GPAs.

A random sample of records of electricity usage of homes gives the amount of electricity used in July 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.Do you think the slope is positive or negative? Why?