Finding the Fourth Proportional to 15,404.34, 21,257.46 and 8,690.16

Step by Step Solution

1. Step 1: Write the proportion equation
   15,404.34 : 21,257.46 = 8,690.16 : x
2. Step 2: Convert to fraction form
   15,404.34/21,257.46 = 8,690.16/x
3. Step 3: Cross multiply
   15,404.34x = 21,257.46 × 8,690.16
4. Step 4: Simplify right side
   15,404.34x = 184,730,728.59
5. Step 5: Solve for x
   x = 184,730,728.59/15,404.34
6. Step 6: Final answer
   x = 11,992.12