Finding the Fourth Proportional to 1,317.72, 1,818.42 and 728.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,317.72 : 1,818.42 = 728.22 : x
2. Step 2: Convert to fraction form
   1,317.72/1,818.42 = 728.22/x
3. Step 3: Cross multiply
   1,317.72x = 1,818.42 × 728.22
4. Step 4: Simplify right side
   1,317.72x = 1,324,209.81
5. Step 5: Solve for x
   x = 1,324,209.81/1,317.72
6. Step 6: Final answer
   x = 1,004.93