Finding the Third Proportional to 139,428 and 210,451.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,428 : 210,451.50 = 210,451.50 : x
2. Step 2: Convert to fraction form
   139,428/210,451.50 = 210,451.50/x
3. Step 3: Cross multiply
   139,428x = 210,451.50 × 210,451.50
4. Step 4: Simplify right side
   139,428x = 44,289,833,852.25
5. Step 5: Solve for x
   x = 44,289,833,852.25/139,428
6. Step 6: Final answer
   x = 317,653.80