Finding the Fourth Proportional to 1,309.72, 1,807.42 and 712.22

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.72 : 1,807.42 = 712.22 : x
2. Step 2: Convert to fraction form
   1,309.72/1,807.42 = 712.22/x
3. Step 3: Cross multiply
   1,309.72x = 1,807.42 × 712.22
4. Step 4: Simplify right side
   1,309.72x = 1,287,280.67
5. Step 5: Solve for x
   x = 1,287,280.67/1,309.72
6. Step 6: Final answer
   x = 982.87