Finding the Third Proportional to 638,856 and 989,064

Step by Step Solution

1. Step 1: Write the proportion equation
   638,856 : 989,064 = 989,064 : x
2. Step 2: Convert to fraction form
   638,856/989,064 = 989,064/x
3. Step 3: Cross multiply
   638,856x = 989,064 × 989,064
4. Step 4: Simplify right side
   638,856x = 978,247,596,096
5. Step 5: Solve for x
   x = 978,247,596,096/638,856
6. Step 6: Final answer
   x = 1,531,248.98