Finding the Fourth Proportional to 139,487.45, 192,415.25 and 91,020.80

Step by Step Solution

1. Step 1: Write the proportion equation
   139,487.45 : 192,415.25 = 91,020.80 : x
2. Step 2: Convert to fraction form
   139,487.45/192,415.25 = 91,020.80/x
3. Step 3: Cross multiply
   139,487.45x = 192,415.25 × 91,020.80
4. Step 4: Simplify right side
   139,487.45x = 17,513,788,570.02
5. Step 5: Solve for x
   x = 17,513,788,570.02/139,487.45
6. Step 6: Final answer
   x = 125,558.17