Finding the Fourth Proportional to 139,979.55, 209,979.60 and 59,939.46

Step by Step Solution

1. Step 1: Write the proportion equation
   139,979.55 : 209,979.60 = 59,939.46 : x
2. Step 2: Convert to fraction form
   139,979.55/209,979.60 = 59,939.46/x
3. Step 3: Cross multiply
   139,979.55x = 209,979.60 × 59,939.46
4. Step 4: Simplify right side
   139,979.55x = 12,586,063,835.02
5. Step 5: Solve for x
   x = 12,586,063,835.02/139,979.55
6. Step 6: Final answer
   x = 89,913.59