Finding the Third Proportional to 145,040 and 316,648

Step by Step Solution

1. Step 1: Write the proportion equation
   145,040 : 316,648 = 316,648 : x
2. Step 2: Convert to fraction form
   145,040/316,648 = 316,648/x
3. Step 3: Cross multiply
   145,040x = 316,648 × 316,648
4. Step 4: Simplify right side
   145,040x = 100,265,955,904
5. Step 5: Solve for x
   x = 100,265,955,904/145,040
6. Step 6: Final answer
   x = 691,298.65