Fuel efficiency of manual and automatic cars, part i. each year the us environmental protection agency (epa) releases fuel economy data on cars manufactured in that year. below are summary statistics on fuel efficiency (in miles/gallon) from random samples of cars with manual and automatic transmissions. do these data provide strong evidence of a difference between the average fuel efficiency of cars with manual and automatic transmissions in terms of their average city mileage? assume that conditions for inference are satisfied.22

Total marketing effort is a term used to describe the critical decision factors that affect demand: price, advertising, distribution, and product quality. define the variable x to represent total marketing effort. a typical model that is used to predict demand as a function of total marketing effort is based on the power function: d = axb suppose that a is a positive number. different model forms result from varying the constant b. sketch the graphs of this model for b = 0, b = 1, 0< b< 1, b< 0, and b> 1. (we encourage you to use excel to do this.) what does each model tell you about the relationship between demand and marketing effort? what assumptions are implied? are they reasonable? how would you go about selecting the appropriate model?