Finding the Fourth Proportional to 1,069.32, 1,472.72 and 921.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,069.32 : 1,472.72 = 921.90 : x
2. Step 2: Convert to fraction form
   1,069.32/1,472.72 = 921.90/x
3. Step 3: Cross multiply
   1,069.32x = 1,472.72 × 921.90
4. Step 4: Simplify right side
   1,069.32x = 1,357,700.57
5. Step 5: Solve for x
   x = 1,357,700.57/1,069.32
6. Step 6: Final answer
   x = 1,269.69