Weizi Yushu

Solution: (1) The frequency of group A is:

( 10÷5)× 1=2( 1)

The capacity of the survey sample is:

(10+2) ÷ (1-40%-28%-8%) = 50 (2 points)

(2) Group C frequency: 50×40%=20(3 minutes),

(3) It is estimated that the number of households who donate not less than 300 yuan is 500×(28%+8%)= 180.