B$.$ How has Tesla$$s business strategy $($or target customer$)$ changed over time? $(3$ points$)$

In $2017,$ Tesla released the Model $3,$ meant to be one of the first affordable electric vehicles. Did the release of a more affordable Model $3$ in $2017$ change Tesla$$s Gross Profit Margin and Inventory Turnover?

Key Variables $($Tesla only$)$:

$$ Gross margin: the $($gross$)$ profit in percentage that the company earns for each car sale

$$ Inventory turnover: how many times the company sold its stock of inventory in the year

Divide the sample into pre$-2017$ and post$-2017$ and compare the average Gross Profit Margin and Inventory Turnover. Please do a t$-$test to test if the difference in both variables is statistically significant.