Finding the Fourth Proportional to 1,009.63, 1,393.59 and 631.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,009.63 : 1,393.59 = 631.72 : x
2. Step 2: Convert to fraction form
   1,009.63/1,393.59 = 631.72/x
3. Step 3: Cross multiply
   1,009.63x = 1,393.59 × 631.72
4. Step 4: Simplify right side
   1,009.63x = 880,358.67
5. Step 5: Solve for x
   x = 880,358.67/1,009.63
6. Step 6: Final answer
   x = 871.96