Finding the Fourth Proportional to 1,152.72, 1,590.75 and 628.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.72 : 1,590.75 = 628.78 : x
2. Step 2: Convert to fraction form
   1,152.72/1,590.75 = 628.78/x
3. Step 3: Cross multiply
   1,152.72x = 1,590.75 × 628.78
4. Step 4: Simplify right side
   1,152.72x = 1,000,231.79
5. Step 5: Solve for x
   x = 1,000,231.79/1,152.72
6. Step 6: Final answer
   x = 867.71