Finding the Fourth Proportional to 2,106.17, 2,906.86 and 1,222.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.17 : 2,906.86 = 1,222.70 : x
2. Step 2: Convert to fraction form
   2,106.17/2,906.86 = 1,222.70/x
3. Step 3: Cross multiply
   2,106.17x = 2,906.86 × 1,222.70
4. Step 4: Simplify right side
   2,106.17x = 3,554,217.72
5. Step 5: Solve for x
   x = 3,554,217.72/2,106.17
6. Step 6: Final answer
   x = 1,687.53