An NBA basketball player is interested if there is an association between the amount of time a player practices his three-point shooting(in hours) and the percentage of three pointers made. Since the NBA player took AP Statistics in high school, he knew of a perfect way to design his study and share it with his NBA friends.
He randomly selected $20$ NBA players and asked them how much time they spent practicing shooting behind the arc (shooting $3$ pointers). He then looked up their three-point percentage. A computer output from fitting a least squares regression line to the data is shown below.
Dependent variable is: % of 3-Pointers Made
$R^2 = 91.24\%$
Which of the following is the standard error of the slope?