Finding the Fourth Proportional to 15,499.84, 21,390.24 and 8,426.72

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.84 : 21,390.24 = 8,426.72 : x
2. Step 2: Convert to fraction form
   15,499.84/21,390.24 = 8,426.72/x
3. Step 3: Cross multiply
   15,499.84x = 21,390.24 × 8,426.72
4. Step 4: Simplify right side
   15,499.84x = 180,249,563.21
5. Step 5: Solve for x
   x = 180,249,563.21/15,499.84
6. Step 6: Final answer
   x = 11,629.12