Question

The weekly observations on cost of living index in a certain city for the year 2004 − 2005 are given below. Compute the weekly cost of living index.

Cost of living Index	Number of Students	Cost of living Index	Number of Students
1400−1500 1500−1600 1600−1700	5 10 20	1700−1800 1800−1900 1900−2000	9 6 2

Answer 1

Let the assumed mean be A = 1650 and h = 100.

We know that mean,

Now, we have.

Putting the values in the above formula, we have

Hence, the mean is 1663.46.