1. The problem asks to find the sum of the values $X - 1$ where $X$ takes the values 5, 10, and 15.
2. First, calculate each term $X - 1$:
$$5 - 1 = 4$$
$$10 - 1 = 9$$
$$15 - 1 = 14$$
3. Now, sum these results:
$$4 + 9 + 14 = 27$$
4. Therefore, the sum $\sum (X - 1)$ for $X = 5, 10, 15$ is $27$.
Final answer: 27
Sum X Minus One Eb6346
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