Finding the Fourth Proportional to 139,345, 192,303.40 and 81,987.28

Step by Step Solution

1. Step 1: Write the proportion equation
   139,345 : 192,303.40 = 81,987.28 : x
2. Step 2: Convert to fraction form
   139,345/192,303.40 = 81,987.28/x
3. Step 3: Cross multiply
   139,345x = 192,303.40 × 81,987.28
4. Step 4: Simplify right side
   139,345x = 15,766,432,700.75
5. Step 5: Solve for x
   x = 15,766,432,700.75/139,345
6. Step 6: Final answer
   x = 113,146.74