Finding the Fourth Proportional to 2,106.28, 2,906.58 and 1,222.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.28 : 2,906.58 = 1,222.12 : x
2. Step 2: Convert to fraction form
   2,106.28/2,906.58 = 1,222.12/x
3. Step 3: Cross multiply
   2,106.28x = 2,906.58 × 1,222.12
4. Step 4: Simplify right side
   2,106.28x = 3,552,189.55
5. Step 5: Solve for x
   x = 3,552,189.55/2,106.28
6. Step 6: Final answer
   x = 1,686.48