Finding the Fourth Proportional to 260,830.02, 391,300.83 and 80,911.55

Step by Step Solution

1. Step 1: Write the proportion equation
   260,830.02 : 391,300.83 = 80,911.55 : x
2. Step 2: Convert to fraction form
   260,830.02/391,300.83 = 80,911.55/x
3. Step 3: Cross multiply
   260,830.02x = 391,300.83 × 80,911.55
4. Step 4: Simplify right side
   260,830.02x = 31,660,754,976.91
5. Step 5: Solve for x
   x = 31,660,754,976.91/260,830.02
6. Step 6: Final answer
   x = 121,384.63