Finding the Fourth Proportional to 1,128.86, 1,557.79 and 631.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.86 : 1,557.79 = 631.52 : x
2. Step 2: Convert to fraction form
   1,128.86/1,557.79 = 631.52/x
3. Step 3: Cross multiply
   1,128.86x = 1,557.79 × 631.52
4. Step 4: Simplify right side
   1,128.86x = 983,775.54
5. Step 5: Solve for x
   x = 983,775.54/1,128.86
6. Step 6: Final answer
   x = 871.48