If 11 AM's are inserted between 28 and 10, than find the three middle terms in the series.

Explanation

To solve the problem of finding the three middle terms when 11 arithmetic means are inserted between 28 and 10, we can follow these steps:

### Step 1: Identify the terms in the series
We have the first term \( a_1 = 28 \) and the last term \( a_{13} = 10 \) (since there are 11 arithmetic means inserted between them, making a total of 13 terms).

### Step 2: Determine the number of terms
The total number of terms \( n = 13 \) (which includes the two endpoints and the 11 means).

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