Finding the Fourth Proportional to 2,108.39, 2,909.78 and 1,212.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,108.39 : 2,909.78 = 1,212.25 : x
2. Step 2: Convert to fraction form
   2,108.39/2,909.78 = 1,212.25/x
3. Step 3: Cross multiply
   2,108.39x = 2,909.78 × 1,212.25
4. Step 4: Simplify right side
   2,108.39x = 3,527,380.81
5. Step 5: Solve for x
   x = 3,527,380.81/2,108.39
6. Step 6: Final answer
   x = 1,673.02