Finding the Fourth Proportional to 2,920.68, 4,381.20 and 972.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,920.68 : 4,381.20 = 972.72 : x
2. Step 2: Convert to fraction form
   2,920.68/4,381.20 = 972.72/x
3. Step 3: Cross multiply
   2,920.68x = 4,381.20 × 972.72
4. Step 4: Simplify right side
   2,920.68x = 4,261,680.86
5. Step 5: Solve for x
   x = 4,261,680.86/2,920.68
6. Step 6: Final answer
   x = 1,459.14