Finding the Fourth Proportional to 89,525.76, 134,821.58 and 77,978.40

Step by Step Solution

1. Step 1: Write the proportion equation
   89,525.76 : 134,821.58 = 77,978.40 : x
2. Step 2: Convert to fraction form
   89,525.76/134,821.58 = 77,978.40/x
3. Step 3: Cross multiply
   89,525.76x = 134,821.58 × 77,978.40
4. Step 4: Simplify right side
   89,525.76x = 10,513,171,093.87
5. Step 5: Solve for x
   x = 10,513,171,093.87/89,525.76
6. Step 6: Final answer
   x = 117,431.80