Finding the Fourth Proportional to 21,200.60, 31,778.76 and 7,155.79

Step by Step Solution

1. Step 1: Write the proportion equation
   21,200.60 : 31,778.76 = 7,155.79 : x
2. Step 2: Convert to fraction form
   21,200.60/31,778.76 = 7,155.79/x
3. Step 3: Cross multiply
   21,200.60x = 31,778.76 × 7,155.79
4. Step 4: Simplify right side
   21,200.60x = 227,402,080.41
5. Step 5: Solve for x
   x = 227,402,080.41/21,200.60
6. Step 6: Final answer
   x = 10,726.21