Finding the Third Proportional to 78,128 and 169,216

Step by Step Solution

1. Step 1: Write the proportion equation
   78,128 : 169,216 = 169,216 : x
2. Step 2: Convert to fraction form
   78,128/169,216 = 169,216/x
3. Step 3: Cross multiply
   78,128x = 169,216 × 169,216
4. Step 4: Simplify right side
   78,128x = 28,634,054,656
5. Step 5: Solve for x
   x = 28,634,054,656/78,128
6. Step 6: Final answer
   x = 366,501.83