"Average" Data Analysis PPT Courseware (Lesson 1)

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"Average" Data Analysis PPT Courseware (Lesson 1)

Part One: Learning Objectives

Understand the concepts of data weights and weighted averages, and appreciate the role of weights (difficulty).

Clarify the relationship between weighted average and arithmetic mean, and master the calculation method of weighted average. (Key points and difficulties)

Average PPT, part 2: knowledge explanation

arithmetic mean

The highest temperatures for a week in mid-July in a certain city are as follows:

1. Can you quickly calculate the average maximum temperature for the week?

2. Have you generalized the concept of arithmetic mean?

Generally, for n numbers x1, x2, …, xn, we put

It is called the arithmetic mean of these n numbers, or the average for short.

weighted average

We call the average 0.17 obtained above as the weighted average of the three numbers 0.15, 0.21, and 0.18. Since the number of people in each suburban county is different, the per capita cultivated land area of ​​each suburban county has a direct relationship with the per capita cultivated land area of ​​the suburban county. The impact is different. Therefore, we call the number of people (unit: 10,000) 15, 7, and 10 in the three suburban counties respectively as three data rights.

"Quan" in English is Weight, which means the importance of data. That is, the power of data reflects the relative "importance" of the data.

Another definition of weighted average

When finding the arithmetic mean of n numbers, if x1 appears f1 times, x2 appears f2 times,..., xk appears fk times (here f1+f2+...+fk=n), then the arithmetic mean of these n numbers

It is also called the weighted average of k numbers x1, x2,...,xk, where f1, f2,..., fk are called the weights of x1, x2,..., xk respectively.

The difference and connection between arithmetic mean and weighted average

1. The arithmetic mean is a special case of the weighted average (it is special in that the weights of each item are equal);

2. In practical problems, when the weights of the various items are not equal, the weighted average must be used to calculate the average. When the weights of the various items are equal, the arithmetic mean must be used to calculate the average.

The meaning of arithmetic mean and weighted average

(1) The arithmetic mean reflects the central tendency of a set of data and reflects the average state of a set of data. To understand the average level of a set of data, you can calculate the arithmetic mean of this set of data. The arithmetic mean is the same as a set of data. Every piece of data has a relationship. When one piece of data changes, it will affect the average of the entire set of data.

(2) The weighted average is not only related to the size of each data, but also affected by the weight of each data. The "weight" of the data reflects the "importance" of the data,

Average PPT, Part 3: Class Summary

Arithmetic mean and weighted average

Arithmetic mean:

weighted average:

The average reflects the central tendency of a set of data

The greater the weight, the greater the proportion of the data; conversely, the smaller the weight, the smaller the proportion of the data.

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For more information about the "Analysis of Data Average" PPT courseware, please click the "Analysis of Data PPT Average PPT" tab.

"Average" data analysis PPT teaching courseware:

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"Average" data analysis PPT download (Lesson 2):

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"Average" data analysis PPT download (Lesson 1):

"Average" data analysis PPT download (Lesson 1), 24 pages in total. The first part of the content: Learning objectives Arithmetic mean Weighted average (weight expressed in proportion or percentage) ... ... ... Average PPT, the second part of the content: Understanding new knowledge Knowledge points...

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Update Time: 2024-07-11

This template belongs to Mathematics courseware People's Education Press Eighth Grade Mathematics Volume 2 industry PPT template

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