Finding the Third Proportional to 54,990 and 83,578.50

Step by Step Solution

1. Step 1: Write the proportion equation
   54,990 : 83,578.50 = 83,578.50 : x
2. Step 2: Convert to fraction form
   54,990/83,578.50 = 83,578.50/x
3. Step 3: Cross multiply
   54,990x = 83,578.50 × 83,578.50
4. Step 4: Simplify right side
   54,990x = 6,985,365,662.25
5. Step 5: Solve for x
   x = 6,985,365,662.25/54,990
6. Step 6: Final answer
   x = 127,029.74