Finding the Fourth Proportional to 12,420.52, 17,140.75 and 7,116.35

Step by Step Solution

1. Step 1: Write the proportion equation
   12,420.52 : 17,140.75 = 7,116.35 : x
2. Step 2: Convert to fraction form
   12,420.52/17,140.75 = 7,116.35/x
3. Step 3: Cross multiply
   12,420.52x = 17,140.75 × 7,116.35
4. Step 4: Simplify right side
   12,420.52x = 121,979,601.32
5. Step 5: Solve for x
   x = 121,979,601.32/12,420.52
6. Step 6: Final answer
   x = 9,820.81