Finding the Fourth Proportional to 680.55, 1,021.34 and 498.42

Step by Step Solution

1. Step 1: Write the proportion equation
   680.55 : 1,021.34 = 498.42 : x
2. Step 2: Convert to fraction form
   680.55/1,021.34 = 498.42/x
3. Step 3: Cross multiply
   680.55x = 1,021.34 × 498.42
4. Step 4: Simplify right side
   680.55x = 509,051.83
5. Step 5: Solve for x
   x = 509,051.83/680.55
6. Step 6: Final answer
   x = 748.00