Finding the Third Proportional to 175.78 and 386.72

Step by Step Solution

1. Step 1: Write the proportion equation
   175.78 : 386.72 = 386.72 : x
2. Step 2: Convert to fraction form
   175.78/386.72 = 386.72/x
3. Step 3: Cross multiply
   175.78x = 386.72 × 386.72
4. Step 4: Simplify right side
   175.78x = 149,551.39
5. Step 5: Solve for x
   x = 149,551.39/175.78
6. Step 6: Final answer
   x = 850.78