Finding the Fourth Proportional to 1,040.91, 1,436.37 and 642.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,040.91 : 1,436.37 = 642.46 : x
2. Step 2: Convert to fraction form
   1,040.91/1,436.37 = 642.46/x
3. Step 3: Cross multiply
   1,040.91x = 1,436.37 × 642.46
4. Step 4: Simplify right side
   1,040.91x = 922,810.27
5. Step 5: Solve for x
   x = 922,810.27/1,040.91
6. Step 6: Final answer
   x = 886.54