The total number of ninth grade students in these five junior high schools is 1840. (2 points)

(2) 1840×( 1-0.4-0. 15-0.2)=460,

1-0.4-0. 15-0.2=0.25,

0.2× 1840-300-5=63; (6 points)

Fractional segment? Frequency? Frequency? ? Under 72 points? 736 ? 0.4? 72-80? 276 ? 0. 15? 8 1-95 points? 460 ? 0.25? 96- 108? 300 0.2? ? 109- 1 19 points? 63? 120 points? 5(3) Reasonable, if the number of people below 72 points is the largest. (8 points)