Finding the Fourth Proportional to 2,109.75, 2,911.90 and 1,225.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.75 : 2,911.90 = 1,225.50 : x
2. Step 2: Convert to fraction form
   2,109.75/2,911.90 = 1,225.50/x
3. Step 3: Cross multiply
   2,109.75x = 2,911.90 × 1,225.50
4. Step 4: Simplify right side
   2,109.75x = 3,568,533.45
5. Step 5: Solve for x
   x = 3,568,533.45/2,109.75
6. Step 6: Final answer
   x = 1,691.45