Finding the Fourth Proportional to 19,609.89, 29,420.33 and 7,931.31

Step by Step Solution

1. Step 1: Write the proportion equation
   19,609.89 : 29,420.33 = 7,931.31 : x
2. Step 2: Convert to fraction form
   19,609.89/29,420.33 = 7,931.31/x
3. Step 3: Cross multiply
   19,609.89x = 29,420.33 × 7,931.31
4. Step 4: Simplify right side
   19,609.89x = 233,341,757.53
5. Step 5: Solve for x
   x = 233,341,757.53/19,609.89
6. Step 6: Final answer
   x = 11,899.19