Finding the Fourth Proportional to 123,538.50, 170,501.42 and 78,220.69

Step by Step Solution

1. Step 1: Write the proportion equation
   123,538.50 : 170,501.42 = 78,220.69 : x
2. Step 2: Convert to fraction form
   123,538.50/170,501.42 = 78,220.69/x
3. Step 3: Cross multiply
   123,538.50x = 170,501.42 × 78,220.69
4. Step 4: Simplify right side
   123,538.50x = 13,336,738,487.68
5. Step 5: Solve for x
   x = 13,336,738,487.68/123,538.50
6. Step 6: Final answer
   x = 107,956.13