Finding the Fourth Proportional to 15,443.11, 21,300.24 and 9,778.78

Step by Step Solution

1. Step 1: Write the proportion equation
   15,443.11 : 21,300.24 = 9,778.78 : x
2. Step 2: Convert to fraction form
   15,443.11/21,300.24 = 9,778.78/x
3. Step 3: Cross multiply
   15,443.11x = 21,300.24 × 9,778.78
4. Step 4: Simplify right side
   15,443.11x = 208,290,360.91
5. Step 5: Solve for x
   x = 208,290,360.91/15,443.11
6. Step 6: Final answer
   x = 13,487.59