Finding the Fourth Proportional to 2,106.87, 2,908.47 and 1,222.35

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.87 : 2,908.47 = 1,222.35 : x
2. Step 2: Convert to fraction form
   2,106.87/2,908.47 = 1,222.35/x
3. Step 3: Cross multiply
   2,106.87x = 2,908.47 × 1,222.35
4. Step 4: Simplify right side
   2,106.87x = 3,555,168.30
5. Step 5: Solve for x
   x = 3,555,168.30/2,106.87
6. Step 6: Final answer
   x = 1,687.42