Finding the Fourth Proportional to 2,111.43, 2,913.31 and 1,215.11

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.43 : 2,913.31 = 1,215.11 : x
2. Step 2: Convert to fraction form
   2,111.43/2,913.31 = 1,215.11/x
3. Step 3: Cross multiply
   2,111.43x = 2,913.31 × 1,215.11
4. Step 4: Simplify right side
   2,111.43x = 3,539,996.36
5. Step 5: Solve for x
   x = 3,539,996.36/2,111.43
6. Step 6: Final answer
   x = 1,676.59