Finding the Fourth Proportional to 498.69, 688.18 and 274.62

Step by Step Solution

1. Step 1: Write the proportion equation
   498.69 : 688.18 = 274.62 : x
2. Step 2: Convert to fraction form
   498.69/688.18 = 274.62/x
3. Step 3: Cross multiply
   498.69x = 688.18 × 274.62
4. Step 4: Simplify right side
   498.69x = 188,983.18
5. Step 5: Solve for x
   x = 188,983.18/498.69
6. Step 6: Final answer
   x = 378.96