Yes they would understand you meant males.
"1/ In economics, the number of males was double that of females, (at/with ) <-150 either , but sentence is not very natural
2/ More female chose to study marketing and accounting than males , with nearly 120 and 200 students respectively
(with is correct for this sentence) with = same as "there is"
1) "1/ In economics, the number of males was double that of females, with 150 males studying economics and only 75 females students. "
1) "At 150 the number of males in the Economics class was double that of Females"
1) with only 75 females in economics they were outnumbered by males by 75" (or by a factor of two) you can also say.