Problem

Light Up My Life $($LUML$)$ Lighting is a manufacturer of low$-$energy lightbulbs for consumers. They are considering two new advertisements that they hope will be more appealing to their potential purchasers. The marketing agency who created the ad created a before$/$after test for the ads with two groups of $1000$ people each. Each group would be exposed to the current ad for a month, and then in the $2$nd and $3$rd months, the test group would see the new ads, while the control group would continue to see the original ad$.$ The ad agency explained that this would compensate for any underlying differences in the two randomly selected groups. Results from the experiment are as follows:

Test Group

$($units sold$)$ Control Group

$($units sold$)$

July $($Original Ad$)4,6705,000$

August $($New Ad $1)6,1306,000$

September $($New Ad $2)6,4805,500$

Question $2$

Using before$/$after experimental design, what is the lift in units for new ad $1($August$)?$