Finding the Fourth Proportional to 1,005.31, 1,387.37 and 632.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.31 : 1,387.37 = 632.15 : x
2. Step 2: Convert to fraction form
   1,005.31/1,387.37 = 632.15/x
3. Step 3: Cross multiply
   1,005.31x = 1,387.37 × 632.15
4. Step 4: Simplify right side
   1,005.31x = 877,015.85
5. Step 5: Solve for x
   x = 877,015.85/1,005.31
6. Step 6: Final answer
   x = 872.39