A finite arithmetic sequence has 7 terms, and the first term is 3/4. What is the difference between the mean and the median of the 7 terms?

- 0
- 3/4
- 4/3
- 3
- 4

**The correct answer is A.**

First term, a = 3/4

Total terms, n = 7

Common difference = d

The nth term = a + (n - 1)d

The median is the middle term, or 4th term = 3/4 + 3d

The mean is the sum of all the terms divided by 7.

S_{n} = n/2 [2a + (n - 1)d]

S_{n} = 7/2 [3/2 + 6d]

Mean = S_{n}/7

Mean = 3/4 + 3d

Because the mean and the median are both 3/4 + 3d, their difference is 0.