Finding the Fourth Proportional to 1,352.56, 1,866.72 and 1,131.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,352.56 : 1,866.72 = 1,131.20 : x
2. Step 2: Convert to fraction form
   1,352.56/1,866.72 = 1,131.20/x
3. Step 3: Cross multiply
   1,352.56x = 1,866.72 × 1,131.20
4. Step 4: Simplify right side
   1,352.56x = 2,111,633.66
5. Step 5: Solve for x
   x = 2,111,633.66/1,352.56
6. Step 6: Final answer
   x = 1,561.21