Finding the Third Proportional to 189.56 and 280.31

Step by Step Solution

1. Step 1: Write the proportion equation
   189.56 : 280.31 = 280.31 : x
2. Step 2: Convert to fraction form
   189.56/280.31 = 280.31/x
3. Step 3: Cross multiply
   189.56x = 280.31 × 280.31
4. Step 4: Simplify right side
   189.56x = 78,575.10
5. Step 5: Solve for x
   x = 78,575.10/189.56
6. Step 6: Final answer
   x = 414.51