Finding the Fourth Proportional to 1,619.28, 2,234.72 and 920.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,619.28 : 2,234.72 = 920.72 : x
2. Step 2: Convert to fraction form
   1,619.28/2,234.72 = 920.72/x
3. Step 3: Cross multiply
   1,619.28x = 2,234.72 × 920.72
4. Step 4: Simplify right side
   1,619.28x = 2,057,551.40
5. Step 5: Solve for x
   x = 2,057,551.40/1,619.28
6. Step 6: Final answer
   x = 1,270.66