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- Tutorials
- 10 Days of Statistics
- Day 0: Weighted Mean

# Day 0: Weighted Mean

# Day 0: Weighted Mean

**Objective**

In the previous challenge, we calculated a *mean*. In this challenge, we practice calculating a *weighted mean*. Check out the Tutorial tab for learning materials and an instructional video!

**Task**

Given an array, , of integers and an array, , representing the respective weights of 's elements, calculate and print the weighted mean of 's elements. Your answer should be rounded to a scale of decimal place (i.e., format).

**Example**

The array of values . Their sum is . The sum of . The weighted mean is . Print and return.

**Function Description**

Complete the *weightedMean* function in the editor below.

*weightedMean* has the following parameters:

- *int X[N]:* an array of values

- *int W[N]:* an array of weights

**Prints**

- *float:* the weighted mean to one decimal place

**Input Format**

The first line contains an integer, , the number of elements in arrays and .

The second line contains space-separated integers that descdribe the elements of array .

The third line contains space-separated integers that descdribe the elements of array .

**Constraints**

- , where is the element of array .
- , where is the element of array .

**Output Format**

Print the *weighted mean* on a new line. Your answer should be rounded to a scale of decimal place (i.e., format).

**Sample Input**

STDIN Function ----- -------- 5 X[] and W[] size n = 5 10 40 30 50 20 X = [10, 40, 30, 50, 20] 1 2 3 4 5 W = [1, 2, 3, 4, 5]

**Sample Output**

```
32.0
```

**Explanation**

We use the following formula to calculate the weighted mean:

And then print our result to a scale of decimal place () on a new line.