Finding the Fourth Proportional to 8,434.58, 12,647.83 and 3,988.55

Step by Step Solution

1. Step 1: Write the proportion equation
   8,434.58 : 12,647.83 = 3,988.55 : x
2. Step 2: Convert to fraction form
   8,434.58/12,647.83 = 3,988.55/x
3. Step 3: Cross multiply
   8,434.58x = 12,647.83 × 3,988.55
4. Step 4: Simplify right side
   8,434.58x = 50,446,429.14
5. Step 5: Solve for x
   x = 50,446,429.14/8,434.58
6. Step 6: Final answer
   x = 5,980.90