Finding the Fourth Proportional to 2,415.72, 3,621.12 and 855.24

Step by Step Solution

1. Step 1: Write the proportion equation
   2,415.72 : 3,621.12 = 855.24 : x
2. Step 2: Convert to fraction form
   2,415.72/3,621.12 = 855.24/x
3. Step 3: Cross multiply
   2,415.72x = 3,621.12 × 855.24
4. Step 4: Simplify right side
   2,415.72x = 3,096,926.67
5. Step 5: Solve for x
   x = 3,096,926.67/2,415.72
6. Step 6: Final answer
   x = 1,281.99