Finding the Fourth Proportional to 2,661.10, 3,991.60 and 929.68

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.10 : 3,991.60 = 929.68 : x
2. Step 2: Convert to fraction form
   2,661.10/3,991.60 = 929.68/x
3. Step 3: Cross multiply
   2,661.10x = 3,991.60 × 929.68
4. Step 4: Simplify right side
   2,661.10x = 3,710,910.69
5. Step 5: Solve for x
   x = 3,710,910.69/2,661.10
6. Step 6: Final answer
   x = 1,394.50