Finding the Fourth Proportional to 2,106.08, 2,906.06 and 1,221.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,106.08 : 2,906.06 = 1,221.70 : x
2. Step 2: Convert to fraction form
   2,106.08/2,906.06 = 1,221.70/x
3. Step 3: Cross multiply
   2,106.08x = 2,906.06 × 1,221.70
4. Step 4: Simplify right side
   2,106.08x = 3,550,333.50
5. Step 5: Solve for x
   x = 3,550,333.50/2,106.08
6. Step 6: Final answer
   x = 1,685.75