Question

The numbers 1, 2, 3 and 4 have weights 0.1, 0.2, 0.3 and 0.4 respectively.

What is the weighted mean?

2.5

2.8

3.0

3.2

Answer 1

Explanation:

To calculate the weighted mean, first multiply each number by its corresponding weight, then add-up the products and divide by the sum of the weights-

weighted mean = (1 x 0.1 + 2 x 0.2 + 3 x 0.3 + 4 x 0.4) / (0.1 + 0.2 + 0.3 + 0.4)

Then simplifying the numerator:-

weighted mean = (0.1 + 0.4 + 0.9 + 1.6) / (0.1 + 0.2 + 0.3 + 0.4)

Then adding up the numerator:-

weighted mean = 3 / 1

So the weighted mean of the numbers 1, 2, 3, and 4 with weights 0.1, 0.2, 0.3, and 0.4 respectively is 3.

Answer 2

1(.1) + 2(.2) + 3(.3) + 4(.4)

= .1 + .4 + .9 + 1.6 = 3.0