Finding the Third Proportional to 253,678.50 and 390,055.50

Step by Step Solution

1. Step 1: Write the proportion equation
   253,678.50 : 390,055.50 = 390,055.50 : x
2. Step 2: Convert to fraction form
   253,678.50/390,055.50 = 390,055.50/x
3. Step 3: Cross multiply
   253,678.50x = 390,055.50 × 390,055.50
4. Step 4: Simplify right side
   253,678.50x = 152,143,293,080.25
5. Step 5: Solve for x
   x = 152,143,293,080.25/253,678.50
6. Step 6: Final answer
   x = 599,748.47