Finding the Third Proportional to 278,438 and 424,185.25

Step by Step Solution

1. Step 1: Write the proportion equation
   278,438 : 424,185.25 = 424,185.25 : x
2. Step 2: Convert to fraction form
   278,438/424,185.25 = 424,185.25/x
3. Step 3: Cross multiply
   278,438x = 424,185.25 × 424,185.25
4. Step 4: Simplify right side
   278,438x = 179,933,126,317.56
5. Step 5: Solve for x
   x = 179,933,126,317.56/278,438
6. Step 6: Final answer
   x = 646,223.31