Finding the Fourth Proportional to 8,309.88, 12,435.55 and 5,191.35

Step by Step Solution

1. Step 1: Write the proportion equation
   8,309.88 : 12,435.55 = 5,191.35 : x
2. Step 2: Convert to fraction form
   8,309.88/12,435.55 = 5,191.35/x
3. Step 3: Cross multiply
   8,309.88x = 12,435.55 × 5,191.35
4. Step 4: Simplify right side
   8,309.88x = 64,557,332.03
5. Step 5: Solve for x
   x = 64,557,332.03/8,309.88
6. Step 6: Final answer
   x = 7,768.75