Finding the Fourth Proportional to 2,128.26, 3,191.48 and 828.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.26 : 3,191.48 = 828.82 : x
2. Step 2: Convert to fraction form
   2,128.26/3,191.48 = 828.82/x
3. Step 3: Cross multiply
   2,128.26x = 3,191.48 × 828.82
4. Step 4: Simplify right side
   2,128.26x = 2,645,162.45
5. Step 5: Solve for x
   x = 2,645,162.45/2,128.26
6. Step 6: Final answer
   x = 1,242.88