Finding the Fourth Proportional to 15,116.71, 20,860.15 and 8,402.12

Step by Step Solution

1. Step 1: Write the proportion equation
   15,116.71 : 20,860.15 = 8,402.12 : x
2. Step 2: Convert to fraction form
   15,116.71/20,860.15 = 8,402.12/x
3. Step 3: Cross multiply
   15,116.71x = 20,860.15 × 8,402.12
4. Step 4: Simplify right side
   15,116.71x = 175,269,483.52
5. Step 5: Solve for x
   x = 175,269,483.52/15,116.71
6. Step 6: Final answer
   x = 11,594.42