Finding the Fourth Proportional to 2,109.25, 2,910.89 and 1,213.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,109.25 : 2,910.89 = 1,213.28 : x
2. Step 2: Convert to fraction form
   2,109.25/2,910.89 = 1,213.28/x
3. Step 3: Cross multiply
   2,109.25x = 2,910.89 × 1,213.28
4. Step 4: Simplify right side
   2,109.25x = 3,531,717.19
5. Step 5: Solve for x
   x = 3,531,717.19/2,109.25
6. Step 6: Final answer
   x = 1,674.40