Finding the Fourth Proportional to 2,109.51, 2,911.08 and 1,225.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.51 : 2,911.08 = 1,225.80 : x
2. Step 2: Convert to fraction form
   2,109.51/2,911.08 = 1,225.80/x
3. Step 3: Cross multiply
   2,109.51x = 2,911.08 × 1,225.80
4. Step 4: Simplify right side
   2,109.51x = 3,568,401.86
5. Step 5: Solve for x
   x = 3,568,401.86/2,109.51
6. Step 6: Final answer
   x = 1,691.58