There will definitely be more people on Saturdays and Sundays than on Mondays to Fridays, because generally everyone signs up for weekend classes.
It depends on the situation of your dance studio. For example, some studios accept mostly school students, so they will have a lot of weekend classes, while some studios accept a lot of professional dancers, and they may have a lot of classes. Dance classes are available Monday through Friday.
To be more specific, there are more boys in the poppin class, because there are very few girls dancing poppin, and poppin is more difficult.
There are more boys in the breaking class, which is also difficult and easy to get injured.
As for Jazz, there are more girls than boys. Because most of them follow the sexy route, girls look better when they jump out, which is also very popular recently.