If the mean deviation about the median of the numbers a, `2a, ....., 50a` is `50,` then |a| equals : (1) 2 (2) 3 (3) 4 (4) 5

Explanation

To solve the problem, we need to find the value of |a| given that the mean deviation about the median of the numbers a, 2a, ..., 50a is 50.

### Step-by-Step Solution:

1. **Identify the Numbers**: The numbers given are a, 2a, 3a, ..., 50a. This is an arithmetic sequence where the first term is a and the last term is 50a.

2. **Calculate the Total Number of Terms**: The total number of terms (n) in this sequence is 50.

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