Answer
Probability that an African-American is a center is
$P$(African-American being a center) =$\frac{34}{284}$ = $11.9718$%
Work Step by Step
Probability (an event) = No of Favorable Outcomes / Total No of Outcomes.
Favorable outcome = African-American is a center = 34 players.
Total no of outcomes = Total African-American players = 284 players.
