Finding the Fourth Proportional to 498.30, 747.72 and 315.78

Step by Step Solution

1. Step 1: Write the proportion equation
   498.30 : 747.72 = 315.78 : x
2. Step 2: Convert to fraction form
   498.30/747.72 = 315.78/x
3. Step 3: Cross multiply
   498.30x = 747.72 × 315.78
4. Step 4: Simplify right side
   498.30x = 236,115.02
5. Step 5: Solve for x
   x = 236,115.02/498.30
6. Step 6: Final answer
   x = 473.84