Finding the Fourth Proportional to 1,409.72, 1,945.28 and 812.05

Step by Step Solution

1. Step 1: Write the proportion equation
   1,409.72 : 1,945.28 = 812.05 : x
2. Step 2: Convert to fraction form
   1,409.72/1,945.28 = 812.05/x
3. Step 3: Cross multiply
   1,409.72x = 1,945.28 × 812.05
4. Step 4: Simplify right side
   1,409.72x = 1,579,655.70
5. Step 5: Solve for x
   x = 1,579,655.70/1,409.72
6. Step 6: Final answer
   x = 1,120.55