Finding the Fourth Proportional to 2,131.43, 3,196.91 and 669.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,131.43 : 3,196.91 = 669.78 : x
2. Step 2: Convert to fraction form
   2,131.43/3,196.91 = 669.78/x
3. Step 3: Cross multiply
   2,131.43x = 3,196.91 × 669.78
4. Step 4: Simplify right side
   2,131.43x = 2,141,223.03
5. Step 5: Solve for x
   x = 2,141,223.03/2,131.43
6. Step 6: Final answer
   x = 1,004.60