Finding the Fourth Proportional to 100,830.78, 139,141.42 and 55,507.60

Step by Step Solution

1. Step 1: Write the proportion equation
   100,830.78 : 139,141.42 = 55,507.60 : x
2. Step 2: Convert to fraction form
   100,830.78/139,141.42 = 55,507.60/x
3. Step 3: Cross multiply
   100,830.78x = 139,141.42 × 55,507.60
4. Step 4: Simplify right side
   100,830.78x = 7,723,406,284.79
5. Step 5: Solve for x
   x = 7,723,406,284.79/100,830.78
6. Step 6: Final answer
   x = 76,597.70