Finding the Fourth Proportional to 1,128.09, 1,556.82 and 630.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.09 : 1,556.82 = 630.79 : x
2. Step 2: Convert to fraction form
   1,128.09/1,556.82 = 630.79/x
3. Step 3: Cross multiply
   1,128.09x = 1,556.82 × 630.79
4. Step 4: Simplify right side
   1,128.09x = 982,022.60
5. Step 5: Solve for x
   x = 982,022.60/1,128.09
6. Step 6: Final answer
   x = 870.52