Finding the Fourth Proportional to 1,128.35, 1,556.06 and 815.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.35 : 1,556.06 = 815.69 : x
2. Step 2: Convert to fraction form
   1,128.35/1,556.06 = 815.69/x
3. Step 3: Cross multiply
   1,128.35x = 1,556.06 × 815.69
4. Step 4: Simplify right side
   1,128.35x = 1,269,250.72
5. Step 5: Solve for x
   x = 1,269,250.72/1,128.35
6. Step 6: Final answer
   x = 1,124.88