Finding the Fourth Proportional to 1,007.82, 1,508.61 and 860.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.82 : 1,508.61 = 860.22 : x
2. Step 2: Convert to fraction form
   1,007.82/1,508.61 = 860.22/x
3. Step 3: Cross multiply
   1,007.82x = 1,508.61 × 860.22
4. Step 4: Simplify right side
   1,007.82x = 1,297,736.49
5. Step 5: Solve for x
   x = 1,297,736.49/1,007.82
6. Step 6: Final answer
   x = 1,287.67