Finding the Fourth Proportional to 1,139.45, 1,572.27 and 719.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.45 : 1,572.27 = 719.60 : x
2. Step 2: Convert to fraction form
   1,139.45/1,572.27 = 719.60/x
3. Step 3: Cross multiply
   1,139.45x = 1,572.27 × 719.60
4. Step 4: Simplify right side
   1,139.45x = 1,131,405.49
5. Step 5: Solve for x
   x = 1,131,405.49/1,139.45
6. Step 6: Final answer
   x = 992.94