Finding the Fourth Proportional to 2,381.91, 3,572.17 and 920.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,381.91 : 3,572.17 = 920.72 : x
2. Step 2: Convert to fraction form
   2,381.91/3,572.17 = 920.72/x
3. Step 3: Cross multiply
   2,381.91x = 3,572.17 × 920.72
4. Step 4: Simplify right side
   2,381.91x = 3,288,968.36
5. Step 5: Solve for x
   x = 3,288,968.36/2,381.91
6. Step 6: Final answer
   x = 1,380.81