Finding the Fourth Proportional to 12,784.43, 17,642.58 and 7,478.21

Step by Step Solution

1. Step 1: Write the proportion equation
   12,784.43 : 17,642.58 = 7,478.21 : x
2. Step 2: Convert to fraction form
   12,784.43/17,642.58 = 7,478.21/x
3. Step 3: Cross multiply
   12,784.43x = 17,642.58 × 7,478.21
4. Step 4: Simplify right side
   12,784.43x = 131,934,918.18
5. Step 5: Solve for x
   x = 131,934,918.18/12,784.43
6. Step 6: Final answer
   x = 10,319.97