Finding the Fourth Proportional to 15,499.74, 21,389.40 and 8,426.10

Step by Step Solution

1. Step 1: Write the proportion equation
   15,499.74 : 21,389.40 = 8,426.10 : x
2. Step 2: Convert to fraction form
   15,499.74/21,389.40 = 8,426.10/x
3. Step 3: Cross multiply
   15,499.74x = 21,389.40 × 8,426.10
4. Step 4: Simplify right side
   15,499.74x = 180,229,223.34
5. Step 5: Solve for x
   x = 180,229,223.34/15,499.74
6. Step 6: Final answer
   x = 11,627.89