Finding the Fourth Proportional to 13,089.71, 18,074.69 and 12,139.97

Step by Step Solution

1. Step 1: Write the proportion equation
   13,089.71 : 18,074.69 = 12,139.97 : x
2. Step 2: Convert to fraction form
   13,089.71/18,074.69 = 12,139.97/x
3. Step 3: Cross multiply
   13,089.71x = 18,074.69 × 12,139.97
4. Step 4: Simplify right side
   13,089.71x = 219,426,134.34
5. Step 5: Solve for x
   x = 219,426,134.34/13,089.71
6. Step 6: Final answer
   x = 16,763.26