Calculating Overall Average Score

A study was conducted to analyze the final exam scores of 200 students in a college-level statistics course. The scores, which ranged from 0 to 100, were distributed among three different categories of students: Freshmen, Sophomores, and Juniors. The mean score for Freshmen was 78, for Sophomores was 82, and for Juniors was 88.

The number of Freshmen in the study was 70, Sophomores were 60, and Juniors were 70. Based on this information, what was the overall average score of all 200 students?