Finding the Third Proportional to 216,270 and 289,291.50

Step by Step Solution

1. Step 1: Write the proportion equation
   216,270 : 289,291.50 = 289,291.50 : x
2. Step 2: Convert to fraction form
   216,270/289,291.50 = 289,291.50/x
3. Step 3: Cross multiply
   216,270x = 289,291.50 × 289,291.50
4. Step 4: Simplify right side
   216,270x = 83,689,571,972.25
5. Step 5: Solve for x
   x = 83,689,571,972.25/216,270
6. Step 6: Final answer
   x = 386,968.01