Finding the Fourth Proportional to 2,477.12, 3,417.40 and 1,638.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,477.12 : 3,417.40 = 1,638.78 : x
2. Step 2: Convert to fraction form
   2,477.12/3,417.40 = 1,638.78/x
3. Step 3: Cross multiply
   2,477.12x = 3,417.40 × 1,638.78
4. Step 4: Simplify right side
   2,477.12x = 5,600,366.77
5. Step 5: Solve for x
   x = 5,600,366.77/2,477.12
6. Step 6: Final answer
   x = 2,260.84