Answer: A. $16.13
Step-by-step explanation:
Total students = 82+74+96+99 =351
Sum of earnings of 82 seniors  = $26.75  x 82= $2193.5
Sum of earnings of 74 juniors  = $12.25 x 74 = $906.5
Sum of earnings of 96 sophomores  = $15.50  x 96 = $1488
Sum of earnings of 99 freshmen  =  $10.85 x 99 = $1074.15
Total earnings = Â $2193.5 Â + $906.5+ Â $1488 +$1074.15
= $5662.15
(Total earnings) ÷ (Total students )
= $5662.15÷ 351
= $16.13