Respuesta :
Answer:
d. 45%
Step-by-step explanation:
According to the frequency table there are 30 sudents who like rock in grades 9-10 and 25 students that like rock and are in grades 11-12.
25 ÷ 55 = n ÷ 100     Â
25 · 100 = 55 · n   Â
2500 ÷ 55 = n     n  = 45.454545     n = 45%
55 is the total amount of students that like rock
25 is the total amount of students that like rock in grades 11-12
100 is the total percentage