Finding the Fourth Proportional to 20,807.72, 31,196.99 and 7,658.38

Step by Step Solution

1. Step 1: Write the proportion equation
   20,807.72 : 31,196.99 = 7,658.38 : x
2. Step 2: Convert to fraction form
   20,807.72/31,196.99 = 7,658.38/x
3. Step 3: Cross multiply
   20,807.72x = 31,196.99 × 7,658.38
4. Step 4: Simplify right side
   20,807.72x = 238,918,404.28
5. Step 5: Solve for x
   x = 238,918,404.28/20,807.72
6. Step 6: Final answer
   x = 11,482.20