Finding the Fourth Proportional to 57,691.39, 86,309.50 and 43,691.86

Step by Step Solution

1. Step 1: Write the proportion equation
   57,691.39 : 86,309.50 = 43,691.86 : x
2. Step 2: Convert to fraction form
   57,691.39/86,309.50 = 43,691.86/x
3. Step 3: Cross multiply
   57,691.39x = 86,309.50 × 43,691.86
4. Step 4: Simplify right side
   57,691.39x = 3,771,022,185.76
5. Step 5: Solve for x
   x = 3,771,022,185.76/57,691.39
6. Step 6: Final answer
   x = 65,365.43