The weekly observations on cost of living index in a certain

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

We know that mean, $\bar{X}=A+h\left(\frac{1}{N} \sum f_{i} u_{i}\right)$

Now, we have $N=\sum f_{i}=52, \sum f_{\mu} u_{i}=7, h=100$ and $A=1650$.

Putting the values in the above formula, we have

$\bar{X}=A+h\left(\frac{1}{N} \sum f_{i} u_{i}\right)$

$=1650+100\left(\frac{1}{52} \times(7)\right)$

$=1650+\frac{700}{52}$

$=1650+13.46$

$=1663.46$

Hence, the mean is 1663.46.