Finding the Fourth Proportional to 2,109.59, 2,911.39 and 1,213.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.59 : 2,911.39 = 1,213.60 : x
2. Step 2: Convert to fraction form
   2,109.59/2,911.39 = 1,213.60/x
3. Step 3: Cross multiply
   2,109.59x = 2,911.39 × 1,213.60
4. Step 4: Simplify right side
   2,109.59x = 3,533,273.22
5. Step 5: Solve for x
   x = 3,533,273.22/2,109.59
6. Step 6: Final answer
   x = 1,674.86