Finding the Third Proportional to 139,396 and 210,390

Step by Step Solution

1. Step 1: Write the proportion equation
   139,396 : 210,390 = 210,390 : x
2. Step 2: Convert to fraction form
   139,396/210,390 = 210,390/x
3. Step 3: Cross multiply
   139,396x = 210,390 × 210,390
4. Step 4: Simplify right side
   139,396x = 44,263,952,100
5. Step 5: Solve for x
   x = 44,263,952,100/139,396
6. Step 6: Final answer
   x = 317,541.05