Finding the Third Proportional to 128.56 and 188.34

Step by Step Solution

1. Step 1: Write the proportion equation
   128.56 : 188.34 = 188.34 : x
2. Step 2: Convert to fraction form
   128.56/188.34 = 188.34/x
3. Step 3: Cross multiply
   128.56x = 188.34 × 188.34
4. Step 4: Simplify right side
   128.56x = 35,473.37
5. Step 5: Solve for x
   x = 35,473.37/128.56
6. Step 6: Final answer
   x = 275.92