An engineer designs an improved engine for a certain make of automobile. the previous design had an average highway gas mileage of 30 mpg (miles per gallon). the new engine has an average highway gas mileage of 30.2 mpg, using a sample of 3600 cars of the model with the new engine. although the difference is quite small, the effect is statistically significant. the explanation is

Quick calculate the roi dollar amount and percentage for these example investments. a. you invest $50 in a government bond that says you can redeem it a year later for $55. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage. b. you invest $200 in stocks and sell them one year later for $230. use the instructions in lesson 3 to calculate the roi dollar amount and percentage. (3.0 points) tip: subtract the initial investment from the total return to get the roi dollar amount. then divide the roi dollar amount by the initial investment, and multiply that number by 100 to get the percentage.