题目

Last year members of a certain professional organization for teachers consisted of teachers from 49 different school districts, with an average (arithmetic mean) of 9.8 schools per district. Last year the average number of teachers at these schools who were members of the organization was 22. Which of the following is closest to the total number of members of the organization last year?

选项

A.

107

B.

106

C.

105

D.

104

E.

103

解析

我们有49个地区,每个地区平均有9.8所学校,每所学校有22名教师。因此,计算如下: \(49×9.8×22 ≈ 5×10×10×10×2 = 10^3×(5×2) = 10^4\) 答案:D
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