Finding the Third Proportional to 189.88 and 389.69

Step by Step Solution

1. Step 1: Write the proportion equation
   189.88 : 389.69 = 389.69 : x
2. Step 2: Convert to fraction form
   189.88/389.69 = 389.69/x
3. Step 3: Cross multiply
   189.88x = 389.69 × 389.69
4. Step 4: Simplify right side
   189.88x = 151,856.35
5. Step 5: Solve for x
   x = 151,856.35/189.88
6. Step 6: Final answer
   x = 799.77