Finding the Fourth Proportional to 2,143.72, 3,216.06 and 989.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,143.72 : 3,216.06 = 989.56 : x
2. Step 2: Convert to fraction form
   2,143.72/3,216.06 = 989.56/x
3. Step 3: Cross multiply
   2,143.72x = 3,216.06 × 989.56
4. Step 4: Simplify right side
   2,143.72x = 3,182,484.33
5. Step 5: Solve for x
   x = 3,182,484.33/2,143.72
6. Step 6: Final answer
   x = 1,484.56