Finding the Fourth Proportional to 2,439.20, 3,658.72 and 977.96

Step by Step Solution

1. Step 1: Write the proportion equation
   2,439.20 : 3,658.72 = 977.96 : x
2. Step 2: Convert to fraction form
   2,439.20/3,658.72 = 977.96/x
3. Step 3: Cross multiply
   2,439.20x = 3,658.72 × 977.96
4. Step 4: Simplify right side
   2,439.20x = 3,578,081.81
5. Step 5: Solve for x
   x = 3,578,081.81/2,439.20
6. Step 6: Final answer
   x = 1,466.91