Finding the Fourth Proportional to 1,076.81, 1,613.15 and 728.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,076.81 : 1,613.15 = 728.43 : x
2. Step 2: Convert to fraction form
   1,076.81/1,613.15 = 728.43/x
3. Step 3: Cross multiply
   1,076.81x = 1,613.15 × 728.43
4. Step 4: Simplify right side
   1,076.81x = 1,175,066.85
5. Step 5: Solve for x
   x = 1,175,066.85/1,076.81
6. Step 6: Final answer
   x = 1,091.25