Finding the Fourth Proportional to 100,987.78, 139,361.21 and 55,047.82

Step by Step Solution

1. Step 1: Write the proportion equation
   100,987.78 : 139,361.21 = 55,047.82 : x
2. Step 2: Convert to fraction form
   100,987.78/139,361.21 = 55,047.82/x
3. Step 3: Cross multiply
   100,987.78x = 139,361.21 × 55,047.82
4. Step 4: Simplify right side
   100,987.78x = 7,671,530,527.82
5. Step 5: Solve for x
   x = 7,671,530,527.82/100,987.78
6. Step 6: Final answer
   x = 75,964.94