Finding the Fourth Proportional to 2,106.40, 2,906.56 and 1,222.08

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.40 : 2,906.56 = 1,222.08 : x
2. Step 2: Convert to fraction form
   2,106.40/2,906.56 = 1,222.08/x
3. Step 3: Cross multiply
   2,106.40x = 2,906.56 × 1,222.08
4. Step 4: Simplify right side
   2,106.40x = 3,552,048.84
5. Step 5: Solve for x
   x = 3,552,048.84/2,106.40
6. Step 6: Final answer
   x = 1,686.31