Finding the Fourth Proportional to 20,793.42, 31,189.59 and 7,640.10

Step by Step Solution

1. Step 1: Write the proportion equation
   20,793.42 : 31,189.59 = 7,640.10 : x
2. Step 2: Convert to fraction form
   20,793.42/31,189.59 = 7,640.10/x
3. Step 3: Cross multiply
   20,793.42x = 31,189.59 × 7,640.10
4. Step 4: Simplify right side
   20,793.42x = 238,291,586.56
5. Step 5: Solve for x
   x = 238,291,586.56/20,793.42
6. Step 6: Final answer
   x = 11,459.95