Answer:
The C) statement is true.
Explanation:
Let's call [tex]x_1[/tex] the average for the first class and [tex]x_2[/tex] the average for the second class. The overall average x is then:
[tex]x=\frac{x_1*18+x_2*24}{18+24}\\x=\frac{84*18+x_2*24}{42}\\x=\frac{1512+x_2*24}{42}[/tex]
Since the average is given by [tex]Average=\frac{Sum of all values}{Amount of values}[/tex]. We can now calculate x assuming the maximun and minimun values of [tex]x_2[/tex], 2400 (which is 100 times 24) and 0 respectivly. That gives:
[tex]x=\frac{1512+2400}{42}\\x=93[/tex]
for it's maximun value and
[tex]x=\frac{1512+0}{42}\\x=36[/tex]
for it's minimun value. So we get that x is between 36% and 93%.
