Finding the Fourth Proportional to 8,985.72, 12,398.32 and 5,449.80

Step by Step Solution

1. Step 1: Write the proportion equation
   8,985.72 : 12,398.32 = 5,449.80 : x
2. Step 2: Convert to fraction form
   8,985.72/12,398.32 = 5,449.80/x
3. Step 3: Cross multiply
   8,985.72x = 12,398.32 × 5,449.80
4. Step 4: Simplify right side
   8,985.72x = 67,568,364.34
5. Step 5: Solve for x
   x = 67,568,364.34/8,985.72
6. Step 6: Final answer
   x = 7,519.53