Chongqing No. 1 Middle School Junior High School Class of 2012 just last week held the final examination of the second semester of the second period of physical education, is now randomly selected as

Chongqing No. 1 Middle School Junior High School Class of 2012 just last week held the final examination of the second semester of the second period of physical education, is now randomly selected as a sample of the results of some students, according to the A (excellent)

Solution: (1) 100;

(2) As shown in the figure:

;

(3) According to the group of A there are 20 people, the total number of 100 people,

∴20 ÷ 100×360 ° = 72 °;

(4) Randomly selected a student's achievement in grade C (6) The probability is: ;

(5) Let the growth rate be x,

∴25(1+x) 2 = 36,

∴x 1 = 0.2 and x 2 = -2.2 (rounded)

∴The growth rate is 20%.