Finding the Fourth Proportional to 1,648.76, 2,471.40 and 1,128.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,648.76 : 2,471.40 = 1,128.62 : x
2. Step 2: Convert to fraction form
   1,648.76/2,471.40 = 1,128.62/x
3. Step 3: Cross multiply
   1,648.76x = 2,471.40 × 1,128.62
4. Step 4: Simplify right side
   1,648.76x = 2,789,271.47
5. Step 5: Solve for x
   x = 2,789,271.47/1,648.76
6. Step 6: Final answer
   x = 1,691.74