Finding the Third Proportional to 1,287.77 and 2,821.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.77 : 2,821.71 = 2,821.71 : x
2. Step 2: Convert to fraction form
   1,287.77/2,821.71 = 2,821.71/x
3. Step 3: Cross multiply
   1,287.77x = 2,821.71 × 2,821.71
4. Step 4: Simplify right side
   1,287.77x = 7,962,052.61
5. Step 5: Solve for x
   x = 7,962,052.61/1,287.77
6. Step 6: Final answer
   x = 6,182.81