Finding the Fourth Proportional to 2,661.22, 3,992.37 and 931.06

Step by Step Solution

1. Step 1: Write the proportion equation
   2,661.22 : 3,992.37 = 931.06 : x
2. Step 2: Convert to fraction form
   2,661.22/3,992.37 = 931.06/x
3. Step 3: Cross multiply
   2,661.22x = 3,992.37 × 931.06
4. Step 4: Simplify right side
   2,661.22x = 3,717,136.01
5. Step 5: Solve for x
   x = 3,717,136.01/2,661.22
6. Step 6: Final answer
   x = 1,396.78