Finding the Fourth Proportional to 12,439, 18,658.86 and 3,205

Step by Step Solution

1. Step 1: Write the proportion equation
   12,439 : 18,658.86 = 3,205 : x
2. Step 2: Convert to fraction form
   12,439/18,658.86 = 3,205/x
3. Step 3: Cross multiply
   12,439x = 18,658.86 × 3,205
4. Step 4: Simplify right side
   12,439x = 59,801,646.30
5. Step 5: Solve for x
   x = 59,801,646.30/12,439
6. Step 6: Final answer
   x = 4,807.59