Finding the Fourth Proportional to 13,089.60, 18,061.56 and 8,615.16

Step by Step Solution

1. Step 1: Write the proportion equation
   13,089.60 : 18,061.56 = 8,615.16 : x
2. Step 2: Convert to fraction form
   13,089.60/18,061.56 = 8,615.16/x
3. Step 3: Cross multiply
   13,089.60x = 18,061.56 × 8,615.16
4. Step 4: Simplify right side
   13,089.60x = 155,603,229.25
5. Step 5: Solve for x
   x = 155,603,229.25/13,089.60
6. Step 6: Final answer
   x = 11,887.55