Finding the Third Proportional to 248,913 and 391,513.50

Step by Step Solution

1. Step 1: Write the proportion equation
   248,913 : 391,513.50 = 391,513.50 : x
2. Step 2: Convert to fraction form
   248,913/391,513.50 = 391,513.50/x
3. Step 3: Cross multiply
   248,913x = 391,513.50 × 391,513.50
4. Step 4: Simplify right side
   248,913x = 153,282,820,682.25
5. Step 5: Solve for x
   x = 153,282,820,682.25/248,913
6. Step 6: Final answer
   x = 615,808.82