Finding the Third Proportional to 215,188 and 439,878

Step by Step Solution

1. Step 1: Write the proportion equation
   215,188 : 439,878 = 439,878 : x
2. Step 2: Convert to fraction form
   215,188/439,878 = 439,878/x
3. Step 3: Cross multiply
   215,188x = 439,878 × 439,878
4. Step 4: Simplify right side
   215,188x = 193,492,654,884
5. Step 5: Solve for x
   x = 193,492,654,884/215,188
6. Step 6: Final answer
   x = 899,179.58