Finding the Fourth Proportional to 2,128.56, 3,193.38 and 830.13

Step by Step Solution

1. Step 1: Write the proportion equation
   2,128.56 : 3,193.38 = 830.13 : x
2. Step 2: Convert to fraction form
   2,128.56/3,193.38 = 830.13/x
3. Step 3: Cross multiply
   2,128.56x = 3,193.38 × 830.13
4. Step 4: Simplify right side
   2,128.56x = 2,650,920.54
5. Step 5: Solve for x
   x = 2,650,920.54/2,128.56
6. Step 6: Final answer
   x = 1,245.41