Lorrie wants to determine the average amount of time that students at her school spend on the computer each day. there are 350 students in 15 classes. the number of boys and girls is approximately equal. which is the most random sample?

"The number of boys and girls is approximately equal" is probably the most random sample, that is if the whole topic of the publication is Lorrie and her experimenting endeavors. If that is not the subject, then "Lorrie wants to determine the average amount of time that students at her school spend on the computer each day" is the most strange and random.

What's the denominator