Finding the Fourth Proportional to 15,499.85, 21,389.94 and 8,426.42

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.85 : 21,389.94 = 8,426.42 : x
2. Step 2: Convert to fraction form
   15,499.85/21,389.94 = 8,426.42/x
3. Step 3: Cross multiply
   15,499.85x = 21,389.94 × 8,426.42
4. Step 4: Simplify right side
   15,499.85x = 180,240,576.08
5. Step 5: Solve for x
   x = 180,240,576.08/15,499.85
6. Step 6: Final answer
   x = 11,628.54