Given the frequency table, what percentage of the students that like rock are also in grades 11–12? round to the nearest whole percent.
band preference for school dance
rap rock country row totals
grades 9–10 40 30 55 125
grades 11–12 60 25 35 120
column totals 100 55 90 245
a. 10%
b. 21%
c. 25%
d. 45%

d. 45%

Step-by-step explanation:

In total there are 30 + 25 = 55 students in total that like rock. From these there are 25 who are in grades 11-12. This makes that (25/55) * 100% = 45.45% of the students that like rock are in grades 11-12.

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          

25 · 100 = 55 · n      

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

26?

step-by-step explanation:

the simplified form is

step-by-step explanation:

we want to simplify the expression,

let us change the middle bar to a normal division sign to obtain,

we multiply the first fraction by the reciprocal of the second fraction to obtain,

we factor to obtain,

we cancel the common factors to get,

we simplify to get,

the correct answer is b