Finding the Fourth Proportional to 3,909.16, 5,863.69 and 987.45

Step by Step Solution

1. Step 1: Write the proportion equation
   3,909.16 : 5,863.69 = 987.45 : x
2. Step 2: Convert to fraction form
   3,909.16/5,863.69 = 987.45/x
3. Step 3: Cross multiply
   3,909.16x = 5,863.69 × 987.45
4. Step 4: Simplify right side
   3,909.16x = 5,790,100.69
5. Step 5: Solve for x
   x = 5,790,100.69/3,909.16
6. Step 6: Final answer
   x = 1,481.16