1 class average = (50 * 3+60 * 5+70 *16+80 * 3+90 *1+100 *12)/.

Class 2 average = (50 * 2+60 * 5+70 *1+80 *12+90 *13+100 * 7)/(2+5+)

Same.

1 class mode 70 points, class 2 90 points.

1 class variance =(50-80)? 0? 5+(60-80)? 0? 5+(70-80)? 0? 5+(80-80)? 0? 5+(90-80)? 0? 5+( 100-80)? 0? 5/(3+5+ 16+3+ 1 1+ 12)=

I won't write in class 2. Maybe I completely forgot the variance.