The average birth weight for a set of quadruplets was 2 lb 12 oz . If the first three babies delivered weighted \( 3 \mathrm{lb} 3 \mathrm{oz}, 2 \mathrm{lb} 11 \mathrm{oz} \), and 2 lb 8 oz respectively, determine the birth weight of the fourth baby that is delivered.

Given: - The average weight of the quadruplets is \( 2\text{ lb } 12\text{ oz} \). - The weights of the first three babies are: - \( 3\text{ lb } 3\text{ oz} \) - \( 2\text{ lb } 11\text{ oz} \) - \( 2\text{ lb } 8\text{ oz} \) **Step 1:** Convert all weights to ounces. Recall \( 1\text{ lb} = 16\text{ oz} \). - Average weight per baby: \[ 2\text{ lb } 12\text{ oz} = 2 \times 16 + 12 = 32 + 12 = 44\text{ oz} \] - Total weight for four babies: \[ 4 \times 44 = 176\text{ oz} \] - First baby: \[ 3\text{ lb } 3\text{ oz} = 3 \times 16 + 3 = 48 + 3 = 51\text{ oz} \] - Second baby: \[ 2\text{ lb } 11\text{ oz} = 2 \times 16 + 11 = 32 + 11 = 43\text{ oz} \] - Third baby: \[ 2\text{ lb } 8\text{ oz} = 2 \times 16 + 8 = 32 + 8 = 40\text{ oz} \] **Step 2:** Sum the weights of the first three babies. \[ 51 + 43 + 40 = 134\text{ oz} \] **Step 3:** Determine the weight of the fourth baby by subtracting the sum of the first three babies from the total weight of the quadruplets. \[ \text{Fourth baby's weight} = 176\text{ oz} - 134\text{ oz} = 42\text{ oz} \] **Step 4:** Convert \( 42\text{ oz} \) back to pounds and ounces. Divide by \( 16 \) (since \( 1\text{ lb} = 16\text{ oz} \)): \[ \text{Pounds} = \left\lfloor \frac{42}{16} \right\rfloor = 2\text{ lb} \] \[ \text{Ounces} = 42 - 2 \times 16 = 42 - 32 = 10\text{ oz} \] Thus, the fourth baby weighs \( 2\text{ lb } 10\text{ oz} \).