Finding the Fourth Proportional to 12,789.30, 17,645.78 and 7,485.42

Step by Step Solution

1. Step 1: Write the proportion equation
   12,789.30 : 17,645.78 = 7,485.42 : x
2. Step 2: Convert to fraction form
   12,789.30/17,645.78 = 7,485.42/x
3. Step 3: Cross multiply
   12,789.30x = 17,645.78 × 7,485.42
4. Step 4: Simplify right side
   12,789.30x = 132,086,074.53
5. Step 5: Solve for x
   x = 132,086,074.53/12,789.30
6. Step 6: Final answer
   x = 10,327.86