Finding the Fourth Proportional to 123,621.28, 170,534.56 and 78,222.72

Step by Step Solution

1. Step 1: Write the proportion equation
   123,621.28 : 170,534.56 = 78,222.72 : x
2. Step 2: Convert to fraction form
   123,621.28/170,534.56 = 78,222.72/x
3. Step 3: Cross multiply
   123,621.28x = 170,534.56 × 78,222.72
4. Step 4: Simplify right side
   123,621.28x = 13,339,677,137.20
5. Step 5: Solve for x
   x = 13,339,677,137.20/123,621.28
6. Step 6: Final answer
   x = 107,907.61