Finding the Fourth Proportional to 101,978.76, 140,735.40 and 56,656.80

Step by Step Solution

1. Step 1: Write the proportion equation
   101,978.76 : 140,735.40 = 56,656.80 : x
2. Step 2: Convert to fraction form
   101,978.76/140,735.40 = 56,656.80/x
3. Step 3: Cross multiply
   101,978.76x = 140,735.40 × 56,656.80
4. Step 4: Simplify right side
   101,978.76x = 7,973,617,410.72
5. Step 5: Solve for x
   x = 7,973,617,410.72/101,978.76
6. Step 6: Final answer
   x = 78,189.00