Finding the Fourth Proportional to 2,112.81, 2,916.09 and 1,228.59

Step by Step Solution

1. Step 1: Write the proportion equation
   2,112.81 : 2,916.09 = 1,228.59 : x
2. Step 2: Convert to fraction form
   2,112.81/2,916.09 = 1,228.59/x
3. Step 3: Cross multiply
   2,112.81x = 2,916.09 × 1,228.59
4. Step 4: Simplify right side
   2,112.81x = 3,582,679.01
5. Step 5: Solve for x
   x = 3,582,679.01/2,112.81
6. Step 6: Final answer
   x = 1,695.69