Finding the Third Proportional to 145,084.50 and 315,090

Step by Step Solution

1. Step 1: Write the proportion equation
   145,084.50 : 315,090 = 315,090 : x
2. Step 2: Convert to fraction form
   145,084.50/315,090 = 315,090/x
3. Step 3: Cross multiply
   145,084.50x = 315,090 × 315,090
4. Step 4: Simplify right side
   145,084.50x = 99,281,708,100
5. Step 5: Solve for x
   x = 99,281,708,100/145,084.50
6. Step 6: Final answer
   x = 684,302.65