Finding the Fourth Proportional to 1,139.76, 1,574.70 and 1,131.48

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.76 : 1,574.70 = 1,131.48 : x
2. Step 2: Convert to fraction form
   1,139.76/1,574.70 = 1,131.48/x
3. Step 3: Cross multiply
   1,139.76x = 1,574.70 × 1,131.48
4. Step 4: Simplify right side
   1,139.76x = 1,781,741.56
5. Step 5: Solve for x
   x = 1,781,741.56/1,139.76
6. Step 6: Final answer
   x = 1,563.26