Then the frequency of 70.5 ~ 80.5 is 1650=0.32, the frequency of 80.5 ~ 90.5 is1-(0.08+0.28+0.32+0.20) = 0.12, and the frequency is 50×
The grouping frequency is 50.5 ~ 60.540.0860.5 ~ 70.5140.2870.5 ~ 80.5160.3280.5 ~ 90.560.1290.5 ~/kloc-.
(2) Students in this school need to strengthen psychological counseling for the following reasons:
According to the meaning of the question, the number of people with more than 70 points is 16+6+ 10=32 (people).
∫ The percentage of people with good mental health is 3250× 100% = 64% < 70%,
Students in this school need to strengthen psychological counseling.