Question

Two distributions with 100 and 200 items have a mean of 20 and 10. Find the combined mean of two

distributions.​

Answer 1

Answer:

The combined mean = 13.33

Explanation:

In the first distribution:

number of observations = 100

mean = 20

Now. mean = sum of all observations / number of observations

=> sum of observations = mean * no. of observations

=> sum of observations = 20 * 100 = 2000 ...........(Eqn 1)

On the same lines, for the second distribution:

number of observations = 200

mean = 10

=> sum of observations = 10 * 200 = 2000 .........(Eqn 2)

For the combined distribution:

number of observations = 100 + 200 = 300

sum of observations = 2000 + 2000 = 4000 ...........(From Eqn 1 and 2)

=> mean = 4000/300

=> mean = 13.33