1. The problem asks to determine $C(0)$ and interpret its value. 2. The function $C(m)$ represents the cost in dollars for using $m$ minutes in a month under a five-person family plan. 3. To find $C(0)$, we look at the cost when $m=0$ minutes. 4. From the given points, when $m=0$, $C=100$. 5. Therefore, $$C(0) = 100$$ 6. Interpretation: This means that even if no minutes are used, the family plan costs 100 dollars per month as a base fee. This is the fixed monthly cost regardless of usage.