Finding the Fourth Proportional to 1,005.86, 1,388.18 and 633.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,005.86 : 1,388.18 = 633.12 : x
2. Step 2: Convert to fraction form
   1,005.86/1,388.18 = 633.12/x
3. Step 3: Cross multiply
   1,005.86x = 1,388.18 × 633.12
4. Step 4: Simplify right side
   1,005.86x = 878,884.52
5. Step 5: Solve for x
   x = 878,884.52/1,005.86
6. Step 6: Final answer
   x = 873.76