Finding the Fourth Proportional to 13,124.72, 18,111.78 and 7,156.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,124.72 : 18,111.78 = 7,156.50 : x
2. Step 2: Convert to fraction form
   13,124.72/18,111.78 = 7,156.50/x
3. Step 3: Cross multiply
   13,124.72x = 18,111.78 × 7,156.50
4. Step 4: Simplify right side
   13,124.72x = 129,616,953.57
5. Step 5: Solve for x
   x = 129,616,953.57/13,124.72
6. Step 6: Final answer
   x = 9,875.79