Finding the Third Proportional to 43,218 and 55,219

Step by Step Solution

1. Step 1: Write the proportion equation
   43,218 : 55,219 = 55,219 : x
2. Step 2: Convert to fraction form
   43,218/55,219 = 55,219/x
3. Step 3: Cross multiply
   43,218x = 55,219 × 55,219
4. Step 4: Simplify right side
   43,218x = 3,049,137,961
5. Step 5: Solve for x
   x = 3,049,137,961/43,218
6. Step 6: Final answer
   x = 70,552.50