Finding the Fourth Proportional to 1,152.81, 1,590.87 and 628.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.81 : 1,590.87 = 628.83 : x
2. Step 2: Convert to fraction form
   1,152.81/1,590.87 = 628.83/x
3. Step 3: Cross multiply
   1,152.81x = 1,590.87 × 628.83
4. Step 4: Simplify right side
   1,152.81x = 1,000,386.78
5. Step 5: Solve for x
   x = 1,000,386.78/1,152.81
6. Step 6: Final answer
   x = 867.78