Finding the Fourth Proportional to 1,089.74, 1,503.15 and 647.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,089.74 : 1,503.15 = 647.31 : x
2. Step 2: Convert to fraction form
   1,089.74/1,503.15 = 647.31/x
3. Step 3: Cross multiply
   1,089.74x = 1,503.15 × 647.31
4. Step 4: Simplify right side
   1,089.74x = 973,004.03
5. Step 5: Solve for x
   x = 973,004.03/1,089.74
6. Step 6: Final answer
   x = 892.88