Finding the Fourth Proportional to 31,593.48, 43,578.42 and 20,978.76

Step by Step Solution

1. Step 1: Write the proportion equation
   31,593.48 : 43,578.42 = 20,978.76 : x
2. Step 2: Convert to fraction form
   31,593.48/43,578.42 = 20,978.76/x
3. Step 3: Cross multiply
   31,593.48x = 43,578.42 × 20,978.76
4. Step 4: Simplify right side
   31,593.48x = 914,221,214.36
5. Step 5: Solve for x
   x = 914,221,214.36/31,593.48
6. Step 6: Final answer
   x = 28,937.02