Finding the Fourth Proportional to 2,128.41, 3,189.78 and 829.17

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.41 : 3,189.78 = 829.17 : x
2. Step 2: Convert to fraction form
   2,128.41/3,189.78 = 829.17/x
3. Step 3: Cross multiply
   2,128.41x = 3,189.78 × 829.17
4. Step 4: Simplify right side
   2,128.41x = 2,644,869.88
5. Step 5: Solve for x
   x = 2,644,869.88/2,128.41
6. Step 6: Final answer
   x = 1,242.65