Step 1: \ \

The sequence is $\"\"$ .

The first term is $\"\"$ .

$\"\"$

The $\"\"$ terms is $\"\"$ .

The $\"\"$ term is $\"\"$ .

The common difference $\"\"$ .

$\"\"$

$\"\"$ .

The common difference $\"\"$ .

Since the common difference is same, the given series is in arithmetic series. \ \

Solution: \ \

The common difference $\"\"$ .

First four terms are $\"\"$ and $\"\"$ .