# Weight vs Mileage

VVAREL

1-According to the transformed model of the association

between weight and mileage, which will save

you more gas: getting rid of the 50 pounds of junk

that you leave in the trunk of your compact car or

removing the 50-pound extra seat from an SUV?

2- A company tracks the level of sales at retail outlets

weekly for 36 weeks. During the first 12 weeks, a fixed

level of advertising was used each week to draw in

customers. During the second 12 weeks, the level of

advertising changed. During the last 12 weeks, a third

level of advertising was used. What does the SRM have

to say about the average level of sales during these

three periods? (Treat sales as Y and advertising as X

and think of the data as 36 weeks of information.)

What business decision might be made as a result of this calculation?

3-Supervisors of an assembly line track the output of

the plant. One tool that they use is a simple regression

of the count of packages shipped each day versus

the number of employees who were active on the

assembly line during that day, which varies from

35 to about 50. Identify a lurking variable that might

violate one of the assumptions of the SRM.

Do you think that is the only lurking variable? Why or why not?

4-As part of locating a new factory, a company investigated

the education and income of the local population.

To keep costs low, the size of the survey of

prospective employees was proportional to the size of

the community. What possible problems for the SRM

would you expect to find in a scatterplot of average

income versus average education for communities of

varying size?