Finding the Fourth Proportional to 31,600.61, 47,389.28 and 12,870.47

Step by Step Solution

1. Step 1: Write the proportion equation
   31,600.61 : 47,389.28 = 12,870.47 : x
2. Step 2: Convert to fraction form
   31,600.61/47,389.28 = 12,870.47/x
3. Step 3: Cross multiply
   31,600.61x = 47,389.28 × 12,870.47
4. Step 4: Simplify right side
   31,600.61x = 609,922,457.21
5. Step 5: Solve for x
   x = 609,922,457.21/31,600.61
6. Step 6: Final answer
   x = 19,300.97