Finding the Fourth Proportional to 31,509.16, 47,268.06 and 13,978.60

Step by Step Solution

1. Step 1: Write the proportion equation
   31,509.16 : 47,268.06 = 13,978.60 : x
2. Step 2: Convert to fraction form
   31,509.16/47,268.06 = 13,978.60/x
3. Step 3: Cross multiply
   31,509.16x = 47,268.06 × 13,978.60
4. Step 4: Simplify right side
   31,509.16x = 660,741,303.52
5. Step 5: Solve for x
   x = 660,741,303.52/31,509.16
6. Step 6: Final answer
   x = 20,969.82