Question $7$

$8$ pts

Suppose we use before$-$after testing to examine the impact of a having a stylist help customers chogre what clothing to buy at Urban Outfitters. We have the following information for the total number of clothing items purchased before $($time $1)$ and after $($time $2)$ the testing is launched. What was the impact of having a stylist help customers? Fill in the missing boxes.

Time $1$

Time $2$

Control Group $($not

provided a stylist$)$

$20$

$21$

Treatment Group $($provided

a stylist$)$

$55$

$68$

"The introduction of the stylists was related to an $($write increase or decrease$)$ in the total number of clothing items purchased of number$)."($write a