GRADE 7 MATH

Data Management Unit Lesson One:

Range, Mean, Median  and Mode

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Class Example

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts70% Drama 76%

2

What is the  RANGE (全距)  of Mr. Au's  marks?

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

3

What is the  RANGE (全距)  of Mr. Au's  marks? The range is the difference between the highest and lowest number.

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

93% ­ 42% = 51% Therefore, the range of Mr. Au's marks is 51%

4

What is the  MEAN (平均) of  Mr. Au's marks?

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

5

What is the  MEAN (平均) of  Mr. Au's marks? Add all the numbers up, and divide it by the number of numbers that you added together.

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

87+75+93+90+77+42+75+88+70+76 = 77.3 10 Therefore, Mr. Au's average is 77.3%

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Mr. Au's Report Card What is the  English 87% MEDIAN (中位数 )  French 75% Math 93% Science 90% of Mr. Au's  Physical Education 77% Health 42% marks? History 75% Geography 88% Visual Arts 70% Drama 76%

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What is the  MEDIAN (中位数 )  of Mr. Au's  marks?

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

The median is the middle number. Arrange your numbers from smallest to biggest and choose the middle number. If TWO numbers are in the middle, then ADD the two numbers together and DIVIDE by 2.

42, 70, 75, 75, 76, 77, 87, 88, 90, 93 (76+77) ÷ 2 = 76.5

Therefore, the median of Mr. Au's mark is  76.5%.

8

What is the  MODE (众数) of  Mr. Au's marks?

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

9

What is the  MODE (众数) of  Mr. Au's marks?

Mr. Au's Report Card English 87% French 75% Math 93% Science 90% Physical Education 77% Health 42% History 75% Geography 88% Visual Arts 70% Drama 76%

The mode is the number that appears the MOST. If TWO numbers appear equally the most number of times, then there are TWO MODES. If NO number appears the most, then there is NO MODE.

The mode of Mr. Au's marks is 75%

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