Finding the Third Proportional to 78.47 and 172.13

Step by Step Solution

1. Step 1: Write the proportion equation
   78.47 : 172.13 = 172.13 : x
2. Step 2: Convert to fraction form
   78.47/172.13 = 172.13/x
3. Step 3: Cross multiply
   78.47x = 172.13 × 172.13
4. Step 4: Simplify right side
   78.47x = 29,627.02
5. Step 5: Solve for x
   x = 29,627.02/78.47
6. Step 6: Final answer
   x = 377.56