Finding the Third Proportional to 275,560 and 390,054

Step by Step Solution

1. Step 1: Write the proportion equation
   275,560 : 390,054 = 390,054 : x
2. Step 2: Convert to fraction form
   275,560/390,054 = 390,054/x
3. Step 3: Cross multiply
   275,560x = 390,054 × 390,054
4. Step 4: Simplify right side
   275,560x = 152,142,122,916
5. Step 5: Solve for x
   x = 152,142,122,916/275,560
6. Step 6: Final answer
   x = 552,119.77