Finding the Fourth Proportional to 43,185.72, 64,780.89 and 13,605.87

Step by Step Solution

1. Step 1: Write the proportion equation
   43,185.72 : 64,780.89 = 13,605.87 : x
2. Step 2: Convert to fraction form
   43,185.72/64,780.89 = 13,605.87/x
3. Step 3: Cross multiply
   43,185.72x = 64,780.89 × 13,605.87
4. Step 4: Simplify right side
   43,185.72x = 881,400,367.82
5. Step 5: Solve for x
   x = 881,400,367.82/43,185.72
6. Step 6: Final answer
   x = 20,409.53