Finding the Fourth Proportional to 1,430.72, 1,974.40 and 809.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,430.72 : 1,974.40 = 809.72 : x
2. Step 2: Convert to fraction form
   1,430.72/1,974.40 = 809.72/x
3. Step 3: Cross multiply
   1,430.72x = 1,974.40 × 809.72
4. Step 4: Simplify right side
   1,430.72x = 1,598,711.17
5. Step 5: Solve for x
   x = 1,598,711.17/1,430.72
6. Step 6: Final answer
   x = 1,117.42