Finding the Third Proportional to 289,944 and 390,168

Step by Step Solution

1. Step 1: Write the proportion equation
   289,944 : 390,168 = 390,168 : x
2. Step 2: Convert to fraction form
   289,944/390,168 = 390,168/x
3. Step 3: Cross multiply
   289,944x = 390,168 × 390,168
4. Step 4: Simplify right side
   289,944x = 152,231,068,224
5. Step 5: Solve for x
   x = 152,231,068,224/289,944
6. Step 6: Final answer
   x = 525,036.10