Finding the Third Proportional to 148,906.50 and 321,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   148,906.50 : 321,139.50 = 321,139.50 : x
2. Step 2: Convert to fraction form
   148,906.50/321,139.50 = 321,139.50/x
3. Step 3: Cross multiply
   148,906.50x = 321,139.50 × 321,139.50
4. Step 4: Simplify right side
   148,906.50x = 103,130,578,460.25
5. Step 5: Solve for x
   x = 103,130,578,460.25/148,906.50
6. Step 6: Final answer
   x = 692,586.14