Finding the Fourth Proportional to 1,309.47, 1,807.61 and 812.67

Step by Step Solution

1. Step 1: Write the proportion equation
   1,309.47 : 1,807.61 = 812.67 : x
2. Step 2: Convert to fraction form
   1,309.47/1,807.61 = 812.67/x
3. Step 3: Cross multiply
   1,309.47x = 1,807.61 × 812.67
4. Step 4: Simplify right side
   1,309.47x = 1,468,990.42
5. Step 5: Solve for x
   x = 1,468,990.42/1,309.47
6. Step 6: Final answer
   x = 1,121.82