Finding the Fourth Proportional to 31,986.34, 47,980.72 and 8,613.38

Step by Step Solution

1. Step 1: Write the proportion equation
   31,986.34 : 47,980.72 = 8,613.38 : x
2. Step 2: Convert to fraction form
   31,986.34/47,980.72 = 8,613.38/x
3. Step 3: Cross multiply
   31,986.34x = 47,980.72 × 8,613.38
4. Step 4: Simplify right side
   31,986.34x = 413,276,174.03
5. Step 5: Solve for x
   x = 413,276,174.03/31,986.34
6. Step 6: Final answer
   x = 12,920.40