Student health in Beijing

(1) According to the stem and leaf atlas, there is excellent data of 10.

∴ The excellent rate is 13,

∴ The total number of outstanding students is 300×13 =100;

(2) The number of healthy students in the sample is 15,

∴ According to the stratified sampling method, 5 students are selected from students with excellent and good physique, so the number of excellent students is 2 and the number of good students is 3;

(1) Choose three students from these five students, and * * has C35= 10 selection methods;

There are at least 1 students with excellent physical fitness among the three selected students. There are nine selection methods: C 12× C23+C22× C 13 =.

∴ The probability that at least 1 of the three selected students has excellent physique is 910;

(2) Among the three students selected, the number of students with excellent physical fitness is not less than that with good physical fitness, C22×C 13=3.

The probability that the number of students with excellent physical fitness is not less than that with good physical fitness is 3 10.