Finding the Third Proportional to 28,398 and 42,990

Step by Step Solution

1. Step 1: Write the proportion equation
   28,398 : 42,990 = 42,990 : x
2. Step 2: Convert to fraction form
   28,398/42,990 = 42,990/x
3. Step 3: Cross multiply
   28,398x = 42,990 × 42,990
4. Step 4: Simplify right side
   28,398x = 1,848,140,100
5. Step 5: Solve for x
   x = 1,848,140,100/28,398
6. Step 6: Final answer
   x = 65,079.94