2、C

3、B

4. A.

5、B

6、C

7、B

8. a

9、70

10、(3.5)、(3)

1 1、( 14)

12、(24)

13, median

14、(360)

15、(87.5)

16、

( 1)(36+34+35+33+37)÷5×50 = 1750kg

(2) 1750×5=8750 yuan

17、

(1) Average temperature: (-9× 2+(-2 )× 2+6× 6+14× 7+20× 5+23× 5+29× 3) ÷ 30 =13.8.

(2) Median: 14, mode: 14.

(3)365×(5+5)/30= 122

18、

Answer: (86× 5+90× 5+96× 4+92× 6) ÷ (5+5+4+6) = 90.8.

b:(92×5+88×5+95×4+93×6)÷(5+5+4+6)= 9 1.9。

So b was hired.