# Question: Let x be the size of a house in square

Let x be the size of a house (in square feet) and y be the amount of natural gas used (therms) during a specified period. Suppose that for a particular community, x and y are related according to the simple linear regression model with b = slope of population regression line = .017 a = y intercept of population regression line = 25.0 Houses in this community range in size from 1000 to 3000 square feet.

a. What is the equation of the population regression line?

b. Graph the population regression line by first finding the point on the line corresponding to x = 1000 and then the point corresponding to x = 2000, and drawing a line through these points.

c. What is the mean value of gas usage for houses with 2100 sq. ft. of space?

d. What is the average change in usage associated with a 1 sq. ft. increase in size?

e. What is the average change in usage associated with a 100 sq. ft. increase in size?

f. Would you use the model to predict mean usage for a 500 sq. ft. house? Why or why not?

a. What is the equation of the population regression line?

b. Graph the population regression line by first finding the point on the line corresponding to x = 1000 and then the point corresponding to x = 2000, and drawing a line through these points.

c. What is the mean value of gas usage for houses with 2100 sq. ft. of space?

d. What is the average change in usage associated with a 1 sq. ft. increase in size?

e. What is the average change in usage associated with a 100 sq. ft. increase in size?

f. Would you use the model to predict mean usage for a 500 sq. ft. house? Why or why not?

## Answer to relevant Questions

A simple linear regression model was used to describe the relationship between y = hardness of molded plastic and x = amount of time elapsed since the end of the molding process. Summary quantities included n 5 15, SSResid = ...Exercise 13. 10 presented y = hardness of molded plastic and x = time elapsed since the molding was completed. Summary quantities included a. Calculate the estimated standard deviation of the statistic b. Obtain a 95% ...Researchers studying pleasant touch sensations measured the firing frequency (impulses per second) of nerves that were stimulated by a light brushing stroke on the forearm and also recorded the subject’s numerical rating ...The article “Vital Dimensions in Volume Perception: Can the Eye Fool the Stomach?” (Journal of Marketing Research [1999]: 313– 326) gave the accompanying data on the dimensions of 27 representative food products ...The data of Exercise13. 25, in which x = milk temperature and y = milk pH, yield a. Obtain a 95% confidence interval for a 1 b(40), the mean milk pH when the milk temperature is 408C. b. Calculate a 99% confidence interval ...Post your question