Finding the Fourth Proportional to 8,321.86, 12,482.76 and 3,390.40

Step by Step Solution

1. Step 1: Write the proportion equation
   8,321.86 : 12,482.76 = 3,390.40 : x
2. Step 2: Convert to fraction form
   8,321.86/12,482.76 = 3,390.40/x
3. Step 3: Cross multiply
   8,321.86x = 12,482.76 × 3,390.40
4. Step 4: Simplify right side
   8,321.86x = 42,321,549.50
5. Step 5: Solve for x
   x = 42,321,549.50/8,321.86
6. Step 6: Final answer
   x = 5,085.59