Finding the Fourth Proportional to 21,378.55, 32,067.90 and 12,607.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,378.55 : 32,067.90 = 12,607.31 : x
2. Step 2: Convert to fraction form
   21,378.55/32,067.90 = 12,607.31/x
3. Step 3: Cross multiply
   21,378.55x = 32,067.90 × 12,607.31
4. Step 4: Simplify right side
   21,378.55x = 404,290,036.52
5. Step 5: Solve for x
   x = 404,290,036.52/21,378.55
6. Step 6: Final answer
   x = 18,911.01