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Question 1:( 1) average 15? , mode 10, median 15.

Question 2: (2) 15×500=7500 tons (2 points

Analysis:

(1) According to the data in

Dongguan Guangming Middle School Mathematics

Question 1:( 1) average 15? , mode 10, median 15.

Question 2: (2) 15×500=7500 tons (2 points

Analysis:

(1) According to the data in

Dongguan Guangming Middle School Mathematics

Question 1:( 1) average 15? , mode 10, median 15.

Question 2: (2) 15×500=7500 tons (2 points

Analysis:

(1) According to the data in the chart, the average, mode and median of 20 data can be obtained;

(2) Using the requirements in (1), the monthly water consumption of the community can be obtained.

(1) average:

10×8+ 15×6+20×4+25×2

20

= 15 ton,

Mode: ∵ maximum water consumption 10 ton, ∴ mode 10 ton;

Median: According to data number. 10, 1 1, both of which are15t, and the median is15t; ?

② The average value is15t,

∴ The monthly water consumption of this community is about:15× 500 = 7,500 tons.

Comments: This topic mainly examines the definitions of average, mode and median, and estimates the population by using samples. It is a key problem in junior high school, and students should focus on it.