Finding the Third Proportional to 276,719.50 and 423,109.50

Step by Step Solution

1. Step 1: Write the proportion equation
   276,719.50 : 423,109.50 = 423,109.50 : x
2. Step 2: Convert to fraction form
   276,719.50/423,109.50 = 423,109.50/x
3. Step 3: Cross multiply
   276,719.50x = 423,109.50 × 423,109.50
4. Step 4: Simplify right side
   276,719.50x = 179,021,648,990.25
5. Step 5: Solve for x
   x = 179,021,648,990.25/276,719.50
6. Step 6: Final answer
   x = 646,942.66