Finding the Fourth Proportional to 1,275.31, 1,760.59 and 1,090.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,275.31 : 1,760.59 = 1,090.78 : x
2. Step 2: Convert to fraction form
   1,275.31/1,760.59 = 1,090.78/x
3. Step 3: Cross multiply
   1,275.31x = 1,760.59 × 1,090.78
4. Step 4: Simplify right side
   1,275.31x = 1,920,417.09
5. Step 5: Solve for x
   x = 1,920,417.09/1,275.31
6. Step 6: Final answer
   x = 1,505.84