Finding the Fourth Proportional to 99,663.89, 137,569.49 and 59,390.28

Step by Step Solution

1. Step 1: Write the proportion equation
   99,663.89 : 137,569.49 = 59,390.28 : x
2. Step 2: Convert to fraction form
   99,663.89/137,569.49 = 59,390.28/x
3. Step 3: Cross multiply
   99,663.89x = 137,569.49 × 59,390.28
4. Step 4: Simplify right side
   99,663.89x = 8,170,290,456.32
5. Step 5: Solve for x
   x = 8,170,290,456.32/99,663.89
6. Step 6: Final answer
   x = 81,978.45