Finding the Third Proportional to 346.78 and 388.55

Step by Step Solution

1. Step 1: Write the proportion equation
   346.78 : 388.55 = 388.55 : x
2. Step 2: Convert to fraction form
   346.78/388.55 = 388.55/x
3. Step 3: Cross multiply
   346.78x = 388.55 × 388.55
4. Step 4: Simplify right side
   346.78x = 150,968.67
5. Step 5: Solve for x
   x = 150,968.67/346.78
6. Step 6: Final answer
   x = 435.34