Finding the Fourth Proportional to 82,613.20, 123,919.86 and 78,406.08

Step by Step Solution

1. Step 1: Write the proportion equation
   82,613.20 : 123,919.86 = 78,406.08 : x
2. Step 2: Convert to fraction form
   82,613.20/123,919.86 = 78,406.08/x
3. Step 3: Cross multiply
   82,613.20x = 123,919.86 × 78,406.08
4. Step 4: Simplify right side
   82,613.20x = 9,716,070,456.75
5. Step 5: Solve for x
   x = 9,716,070,456.75/82,613.20
6. Step 6: Final answer
   x = 117,609.18