130 ~ 140 The number of people in the fractional section is 2, and the statistical chart shows that

Frequency =0.005× group spacing =0.05

Frequency = frequency/total, so total = frequency/frequency = 2/0.05 =40.

Therefore, the conclusion is:

A * * * made statistics on 40 students, that is, there were 40 students whose grades were between 90- 140.

(2)

The Gold Partner Group has the following six combinations:

Group 1+ group 3; Group 1+ group 4; Group 1+ group 5;

The second group+the fourth group; Group 2+Group 5; Group 3+ Group 5.

The situation of the two groups is: c (5,2) =10.

So the probability is: 6/ 10 =0.6 =60%.

(3)

The number of people between 90 and 100 is 0.0 10× 10×40 = 4 people.

The number of people from 100 to10 is 0.025× 10×40 = 10.

The number of people from 1 10 to 120 is 0.045× 10×40 = 18.

When there are 40 participants, the median should be between 20th and 2nd1,in descending order.

So the median should be between 1 10 and 120.