Finding the Fourth Proportional to 15,663.86, 21,612.72 and 9,287.30

Step by Step Solution

1. Step 1: Write the proportion equation
   15,663.86 : 21,612.72 = 9,287.30 : x
2. Step 2: Convert to fraction form
   15,663.86/21,612.72 = 9,287.30/x
3. Step 3: Cross multiply
   15,663.86x = 21,612.72 × 9,287.30
4. Step 4: Simplify right side
   15,663.86x = 200,723,706.39
5. Step 5: Solve for x
   x = 200,723,706.39/15,663.86
6. Step 6: Final answer
   x = 12,814.45