Finding the Fourth Proportional to 8,145.28, 12,209.35 and 5,185.99

Step by Step Solution

1. Step 1: Write the proportion equation
   8,145.28 : 12,209.35 = 5,185.99 : x
2. Step 2: Convert to fraction form
   8,145.28/12,209.35 = 5,185.99/x
3. Step 3: Cross multiply
   8,145.28x = 12,209.35 × 5,185.99
4. Step 4: Simplify right side
   8,145.28x = 63,317,567.01
5. Step 5: Solve for x
   x = 63,317,567.01/8,145.28
6. Step 6: Final answer
   x = 7,773.53