Finding the Third Proportional to 218,916 and 279,727.50

Step by Step Solution

1. Step 1: Write the proportion equation
   218,916 : 279,727.50 = 279,727.50 : x
2. Step 2: Convert to fraction form
   218,916/279,727.50 = 279,727.50/x
3. Step 3: Cross multiply
   218,916x = 279,727.50 × 279,727.50
4. Step 4: Simplify right side
   218,916x = 78,247,474,256.25
5. Step 5: Solve for x
   x = 78,247,474,256.25/218,916
6. Step 6: Final answer
   x = 357,431.50