Finding the Third Proportional to 148.78 and 314.72

Step by Step Solution

1. Step 1: Write the proportion equation
   148.78 : 314.72 = 314.72 : x
2. Step 2: Convert to fraction form
   148.78/314.72 = 314.72/x
3. Step 3: Cross multiply
   148.78x = 314.72 × 314.72
4. Step 4: Simplify right side
   148.78x = 99,047.89
5. Step 5: Solve for x
   x = 99,047.89/148.78
6. Step 6: Final answer
   x = 665.73