Question

The arithmetic mean of 1, 2, 3, ... , n is

विकल्प

• \[\frac{n + 1}{2}\]

• \[\frac{n - 1}{2}\]

• \[\frac{n}{2}\]

• \[\frac{n}{2} + 1\]

Answer 1

Arithmetic mean of 1, 2, 3, ... , n

\[= \frac{1 + 2 + 3 + . . . + n}{n}\]

\[ = \frac{\frac{n\left( n + 1 \right)}{2}}{n}\]

\[ = \frac{n + 1}{2}\]

Hence, the correct option is (a).