加权平均值与平均值

A weighted average is one that takes into account the importance, or weight, of each value. This article will show you how to use Excel’s SUMPRODUCT and SUM functions individually and how to combine the two to calculate a weighted average.

加权平均值是考虑到每个值的重要性或权重的平均值。 本文将向您展示如何分别使用Excel的SUMPRODUCT和SUM函数，以及如何将两者结合起来以计算加权平均值。

什么是加权平均值？ (What is a Weighted Average?)

A weighted average is an average that takes into account the importance, or weight, of each value.  A good example would be calculating a student’s final grade based on their performance on a variety of different assignments and tests. Individual assignments usually don’t count as much towards a final grade as the final exam—things like quizzes, tests, and final exams will all have different weights. The weighted average is calculated as the sum of all of the values multiplied by their weights divided by the sum of all of the weights.

加权平均值是考虑每个值的重要性或权重的平均值。 一个很好的例子是根据学生在各种不同的作业和测验中的表现来计算他们的最终成绩。 通常，个人作业对期末成绩的重视程度不及期末考试的重要程度，例如测验，测试和期末考试的权重都不同。 加权平均值计算为所有值的总和乘以其权重再除以所有权重的总和。

The following example will demonstrate how to use Excel’s SUMPRODUCT and SUM functions to calculate a weighted average.

下面的示例将演示如何使用Excel的SUMPRODUCT和SUM函数来计算加权平均值。

让我们看一个例子 (Let’s Look at an Example)

For our example, let’s look at a student’s quiz and exam scores. There are six quizzes each worth 5% of the total grade, two exams each worth 20% of the total grade, and one final exam worth 30% of the total grade.  The student’s final grade will be a weighted average, and we will use the SUMPRODUCT and SUM functions to calculate it.

对于我们的示例，让我们看一下学生的测验和考试成绩。 有6个测验，每个测验占总成绩的5％；两个测验，每个测验占总成绩的20％；以及一个期末测验，占测验总值的30％。 学生的最终成绩将是加权平均值，我们将使用SUMPRODUCT和SUM函数进行计算。

As you can see in our table below, we’ve already assigned the relative weights to each quiz and exam in the D column.

如您在下表中所见，我们已经在D列中为每个测验和考试分配了相对权重。

第一步：计算SUMPRODUCT (Step One: Calculate the SUMPRODUCT)

First, let’s look at how the SUMPRODUCT function works. Start by selecting the cell where you want the result to appear (in our example, that’s cell D13). Next, navigate to the “Formulas” menu, select the “Math & Trig” drop-down, scroll to the bottom, and click on the “SUMPRODUCT” function.

首先，让我们看一下SUMPRODUCT函数的工作方式。 首先选择要在其中显示结果的单元格(在我们的示例中为D13单元格)。 接下来，导航到“公式”菜单，选择“数学和触发”下拉菜单，滚动到底部，然后单击“ SUMPRODUCT”功能。

The “Function Arguments” window will appear.

出现“功能参数”窗口。

For the “Array1” box, select the student’s scores. Here, we’re selecting all the cells with actual scores in the C column.

对于“ Array1”框，选择学生的分数。 在这里，我们选择C列中所有具有实际分数的单元格。

Next, use the “Array2” box to select the weights of the quizzes and exams. For us, those are in the D column.

接下来，使用“ Array2”框选择测验和检查的权重。 对我们来说，这些在D列中。

Click “OK” when you’re done.

完成后，单击“确定”。

The SUMPRODUCT function will multiply each score by its corresponding weight and then return the sum of all of those products.

SUMPRODUCT函数将每个分数乘以其相应的权重，然后返回所有这些乘积的总和。

第二步：计算总和 (Step Two: Calculate the SUM)

Now let’s look at how the SUM function works. Select the cell where you want the results to appear (in our example, that’s cell D14). Next, navigate to the “Formulas” menu, select the “Math & Trig” drop-down, scroll to the bottom, and click on the “SUM” function.

现在让我们看一下SUM函数的工作方式。 选择要在其中显示结果的单元格(在我们的示例中，为单元格D14)。 接下来，导航到“公式”菜单，选择“数学和触发”下拉菜单，滚动到底部，然后单击“求和”功能。

The “Function Arguments” window will appear.

出现“功能参数”窗口。

For the “Number1” box, select all of the weights.

对于“ Number1”框，选择所有权重。

Click “OK.”

点击“确定”。

The SUM function will add all of the values together.

SUM函数会将所有值加在一起。

第三步：结合SUMPRODUCT和SUM来计算加权平均值 (Step Three: Combine the SUMPRODUCT and SUM to Calculate the Weighted Average)

Now we can combine the two functions to determine the student’s final grade based on their scores and the weights of each score. Select the cell where the weighted average should go (for us that’s cell D15) and then type the following formula into the function bar.

现在，我们可以结合这两个功能，根据学生的分数和每个分数的权重来确定其最终成绩。 选择加权平均值应到达的单元格(对于我们来说是D15单元格)，然后在功能栏中键入以下公式。

=SUMPRODUCT(C3:C11,D3:D11)/SUM(D3:D11)

Press “Enter” after typing the formula to view the weighted average.

输入公式后，按“ Enter”以查看加权平均值。

And there you have it. It’s a fairly simple example, but it’s a good one for showing how weighted averages work.

那里有。 这是一个非常简单的示例，但是它是展示加权平均值的工作原理的一个很好的例子。

翻译自: https://www.howtogeek.com/401826/how-to-calculate-a-weighted-average-in-excel/

加权平均值与平均值