Finding the Fourth Proportional to 11,899.20, 16,415.60 and 8,364.72

Step by Step Solution

1. Step 1: Write the proportion equation
   11,899.20 : 16,415.60 = 8,364.72 : x
2. Step 2: Convert to fraction form
   11,899.20/16,415.60 = 8,364.72/x
3. Step 3: Cross multiply
   11,899.20x = 16,415.60 × 8,364.72
4. Step 4: Simplify right side
   11,899.20x = 137,311,897.63
5. Step 5: Solve for x
   x = 137,311,897.63/11,899.20
6. Step 6: Final answer
   x = 11,539.59