Finding the Fourth Proportional to 1,039.57, 1,559.86 and 491.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.57 : 1,559.86 = 491.10 : x
2. Step 2: Convert to fraction form
   1,039.57/1,559.86 = 491.10/x
3. Step 3: Cross multiply
   1,039.57x = 1,559.86 × 491.10
4. Step 4: Simplify right side
   1,039.57x = 766,040.17
5. Step 5: Solve for x
   x = 766,040.17/1,039.57
6. Step 6: Final answer
   x = 736.88