Finding the Fourth Proportional to 11,321.60, 15,638.76 and 9,439.34

Step by Step Solution

1. Step 1: Write the proportion equation
   11,321.60 : 15,638.76 = 9,439.34 : x
2. Step 2: Convert to fraction form
   11,321.60/15,638.76 = 9,439.34/x
3. Step 3: Cross multiply
   11,321.60x = 15,638.76 × 9,439.34
4. Step 4: Simplify right side
   11,321.60x = 147,619,572.82
5. Step 5: Solve for x
   x = 147,619,572.82/11,321.60
6. Step 6: Final answer
   x = 13,038.76