Finding the Third Proportional to 145,993 and 315,290

Step by Step Solution

1. Step 1: Write the proportion equation
   145,993 : 315,290 = 315,290 : x
2. Step 2: Convert to fraction form
   145,993/315,290 = 315,290/x
3. Step 3: Cross multiply
   145,993x = 315,290 × 315,290
4. Step 4: Simplify right side
   145,993x = 99,407,784,100
5. Step 5: Solve for x
   x = 99,407,784,100/145,993
6. Step 6: Final answer
   x = 680,907.88