Finding the Fourth Proportional to 1,007.00, 1,390.07 and 866.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,007.00 : 1,390.07 = 866.55 : x
2. Step 2: Convert to fraction form
   1,007.00/1,390.07 = 866.55/x
3. Step 3: Cross multiply
   1,007.00x = 1,390.07 × 866.55
4. Step 4: Simplify right side
   1,007.00x = 1,204,560.83
5. Step 5: Solve for x
   x = 1,204,560.83/1,007.00
6. Step 6: Final answer
   x = 1,196.19