Finding the Fourth Proportional to 1,139.99, 1,571.73 and 766.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.99 : 1,571.73 = 766.37 : x
2. Step 2: Convert to fraction form
   1,139.99/1,571.73 = 766.37/x
3. Step 3: Cross multiply
   1,139.99x = 1,571.73 × 766.37
4. Step 4: Simplify right side
   1,139.99x = 1,204,526.72
5. Step 5: Solve for x
   x = 1,204,526.72/1,139.99
6. Step 6: Final answer
   x = 1,056.61