Finding the Fourth Proportional to 1,147.70, 1,584.25 and 728.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,147.70 : 1,584.25 = 728.78 : x
2. Step 2: Convert to fraction form
   1,147.70/1,584.25 = 728.78/x
3. Step 3: Cross multiply
   1,147.70x = 1,584.25 × 728.78
4. Step 4: Simplify right side
   1,147.70x = 1,154,569.72
5. Step 5: Solve for x
   x = 1,154,569.72/1,147.70
6. Step 6: Final answer
   x = 1,005.99