Finding the Fourth Proportional to 12,961.89, 17,890.33 and 7,930.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,961.89 : 17,890.33 = 7,930.31 : x
2. Step 2: Convert to fraction form
   12,961.89/17,890.33 = 7,930.31/x
3. Step 3: Cross multiply
   12,961.89x = 17,890.33 × 7,930.31
4. Step 4: Simplify right side
   12,961.89x = 141,875,773.45
5. Step 5: Solve for x
   x = 141,875,773.45/12,961.89
6. Step 6: Final answer
   x = 10,945.61