Find the mean deviation about the mean for the data :`x_i` 10 30 50 70 90`f_i` 4 24 28 16 8

Explanation

To find the mean deviation about the mean for the given data, we will follow these steps:

### Step 1: Calculate the Mean (x̄)

We will use the formula for the mean:

\[
\bar{x} = \frac{\sum (x_i \cdot f_i)}{\sum f_i}
...