Finding the Fourth Proportional to 20,978.91, 31,464.18 and 13,460.22

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.91 : 31,464.18 = 13,460.22 : x
2. Step 2: Convert to fraction form
   20,978.91/31,464.18 = 13,460.22/x
3. Step 3: Cross multiply
   20,978.91x = 31,464.18 × 13,460.22
4. Step 4: Simplify right side
   20,978.91x = 423,514,784.92
5. Step 5: Solve for x
   x = 423,514,784.92/20,978.91
6. Step 6: Final answer
   x = 20,187.64