Finding the Fourth Proportional to 12,380.21, 17,087.66 and 7,078.12

Step by Step Solution

1. Step 1: Write the proportion equation
   12,380.21 : 17,087.66 = 7,078.12 : x
2. Step 2: Convert to fraction form
   12,380.21/17,087.66 = 7,078.12/x
3. Step 3: Cross multiply
   12,380.21x = 17,087.66 × 7,078.12
4. Step 4: Simplify right side
   12,380.21x = 120,948,456.43
5. Step 5: Solve for x
   x = 120,948,456.43/12,380.21
6. Step 6: Final answer
   x = 9,769.50