Step 1: Understanding the Concept:
For an odd number of consecutive integers in arithmetic progression, the average equals the exact middle number.
Step 2: Key Formula or Approach:
Let the 7 consecutive numbers be $x-3, x-2, x-1, x, x+1, x+2, x+3$.
The middle number (4th term) is the average, so $x = 20$.
The complete set of 7 consecutive integers is $17, 18, 19, 20, 21, 22, 23$.
Step 3: Detailed Explanation:
The largest number in the series is:
\[\text{Largest} = x + 3 = 20 + 3 = 23\]
Step 4: Final Answer:
Thus, the largest number is 23.