Finding the Fourth Proportional to 139,415.99, 209,006.42 and 60,470.78

Step by Step Solution

1. Step 1: Write the proportion equation
   139,415.99 : 209,006.42 = 60,470.78 : x
2. Step 2: Convert to fraction form
   139,415.99/209,006.42 = 60,470.78/x
3. Step 3: Cross multiply
   139,415.99x = 209,006.42 × 60,470.78
4. Step 4: Simplify right side
   139,415.99x = 12,638,779,895.02
5. Step 5: Solve for x
   x = 12,638,779,895.02/139,415.99
6. Step 6: Final answer
   x = 90,655.17