Finding the Fourth Proportional to 1,139.27, 1,570.79 and 1,000.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.27 : 1,570.79 = 1,000.76 : x
2. Step 2: Convert to fraction form
   1,139.27/1,570.79 = 1,000.76/x
3. Step 3: Cross multiply
   1,139.27x = 1,570.79 × 1,000.76
4. Step 4: Simplify right side
   1,139.27x = 1,571,978.45
5. Step 5: Solve for x
   x = 1,571,978.45/1,139.27
6. Step 6: Final answer
   x = 1,379.82