Finding the Fourth Proportional to 101,128.76, 139,557.56 and 55,806.72

Step by Step Solution

1. Step 1: Write the proportion equation
   101,128.76 : 139,557.56 = 55,806.72 : x
2. Step 2: Convert to fraction form
   101,128.76/139,557.56 = 55,806.72/x
3. Step 3: Cross multiply
   101,128.76x = 139,557.56 × 55,806.72
4. Step 4: Simplify right side
   101,128.76x = 7,788,249,674.80
5. Step 5: Solve for x
   x = 7,788,249,674.80/101,128.76
6. Step 6: Final answer
   x = 77,013.20