Finding the Fourth Proportional to 1,152.52, 1,728.78 and 421.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.52 : 1,728.78 = 421.81 : x
2. Step 2: Convert to fraction form
   1,152.52/1,728.78 = 421.81/x
3. Step 3: Cross multiply
   1,152.52x = 1,728.78 × 421.81
4. Step 4: Simplify right side
   1,152.52x = 729,216.69
5. Step 5: Solve for x
   x = 729,216.69/1,152.52
6. Step 6: Final answer
   x = 632.72