Finding the Fourth Proportional to 1,128.05, 1,556.69 and 630.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.05 : 1,556.69 = 630.60 : x
2. Step 2: Convert to fraction form
   1,128.05/1,556.69 = 630.60/x
3. Step 3: Cross multiply
   1,128.05x = 1,556.69 × 630.60
4. Step 4: Simplify right side
   1,128.05x = 981,648.71
5. Step 5: Solve for x
   x = 981,648.71/1,128.05
6. Step 6: Final answer
   x = 870.22