Finding the Fourth Proportional to 5,616.72, 8,415.72 and 3,418.80

Step by Step Solution

1. Step 1: Write the proportion equation
   5,616.72 : 8,415.72 = 3,418.80 : x
2. Step 2: Convert to fraction form
   5,616.72/8,415.72 = 3,418.80/x
3. Step 3: Cross multiply
   5,616.72x = 8,415.72 × 3,418.80
4. Step 4: Simplify right side
   5,616.72x = 28,771,663.54
5. Step 5: Solve for x
   x = 28,771,663.54/5,616.72
6. Step 6: Final answer
   x = 5,122.50