Finding the Fourth Proportional to 1,077.12, 1,488.24 and 816.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,077.12 : 1,488.24 = 816.48 : x
2. Step 2: Convert to fraction form
   1,077.12/1,488.24 = 816.48/x
3. Step 3: Cross multiply
   1,077.12x = 1,488.24 × 816.48
4. Step 4: Simplify right side
   1,077.12x = 1,215,118.20
5. Step 5: Solve for x
   x = 1,215,118.20/1,077.12
6. Step 6: Final answer
   x = 1,128.12