Finding the Fourth Proportional to 28,588.25, 42,897 and 13,612.31

Step by Step Solution

1. Step 1: Write the proportion equation
   28,588.25 : 42,897 = 13,612.31 : x
2. Step 2: Convert to fraction form
   28,588.25/42,897 = 13,612.31/x
3. Step 3: Cross multiply
   28,588.25x = 42,897 × 13,612.31
4. Step 4: Simplify right side
   28,588.25x = 583,927,047.59
5. Step 5: Solve for x
   x = 583,927,047.59/28,588.25
6. Step 6: Final answer
   x = 20,425.42