Finding the Third Proportional to 421.31 and 498.56

Step by Step Solution

1. Step 1: Write the proportion equation
   421.31 : 498.56 = 498.56 : x
2. Step 2: Convert to fraction form
   421.31/498.56 = 498.56/x
3. Step 3: Cross multiply
   421.31x = 498.56 × 498.56
4. Step 4: Simplify right side
   421.31x = 248,564.57
5. Step 5: Solve for x
   x = 248,564.57/421.31
6. Step 6: Final answer
   x = 589.98