Finding the Fourth Proportional to 498.38, 687.76 and 291.38

Step by Step Solution

1. Step 1: Write the proportion equation
   498.38 : 687.76 = 291.38 : x
2. Step 2: Convert to fraction form
   498.38/687.76 = 291.38/x
3. Step 3: Cross multiply
   498.38x = 687.76 × 291.38
4. Step 4: Simplify right side
   498.38x = 200,395.34
5. Step 5: Solve for x
   x = 200,395.34/498.38
6. Step 6: Final answer
   x = 402.10