Finding the Fourth Proportional to 1,100.76, 1,650.65 and 407.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,100.76 : 1,650.65 = 407.31 : x
2. Step 2: Convert to fraction form
   1,100.76/1,650.65 = 407.31/x
3. Step 3: Cross multiply
   1,100.76x = 1,650.65 × 407.31
4. Step 4: Simplify right side
   1,100.76x = 672,324.21
5. Step 5: Solve for x
   x = 672,324.21/1,100.76
6. Step 6: Final answer
   x = 610.78