Finding the Fourth Proportional to 28,645.86, 39,550.56 and 21,919.47

Step by Step Solution

1. Step 1: Write the proportion equation
   28,645.86 : 39,550.56 = 21,919.47 : x
2. Step 2: Convert to fraction form
   28,645.86/39,550.56 = 21,919.47/x
3. Step 3: Cross multiply
   28,645.86x = 39,550.56 × 21,919.47
4. Step 4: Simplify right side
   28,645.86x = 866,927,313.40
5. Step 5: Solve for x
   x = 866,927,313.40/28,645.86
6. Step 6: Final answer
   x = 30,263.62