Finding the Fourth Proportional to 78,390.56, 117,737.10 and 67,171.25

Step by Step Solution

1. Step 1: Write the proportion equation
   78,390.56 : 117,737.10 = 67,171.25 : x
2. Step 2: Convert to fraction form
   78,390.56/117,737.10 = 67,171.25/x
3. Step 3: Cross multiply
   78,390.56x = 117,737.10 × 67,171.25
4. Step 4: Simplify right side
   78,390.56x = 7,908,547,589.69
5. Step 5: Solve for x
   x = 7,908,547,589.69/78,390.56
6. Step 6: Final answer
   x = 100,886.49