Finding the Fourth Proportional to 2,074.38, 3,111.24 and 687.66

Step by Step Solution

1. Step 1: Write the proportion equation
   2,074.38 : 3,111.24 = 687.66 : x
2. Step 2: Convert to fraction form
   2,074.38/3,111.24 = 687.66/x
3. Step 3: Cross multiply
   2,074.38x = 3,111.24 × 687.66
4. Step 4: Simplify right side
   2,074.38x = 2,139,475.30
5. Step 5: Solve for x
   x = 2,139,475.30/2,074.38
6. Step 6: Final answer
   x = 1,031.38