Finding the Fourth Proportional to 2,017.92, 2,786.88 and 1,987.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,017.92 : 2,786.88 = 1,987.20 : x
2. Step 2: Convert to fraction form
   2,017.92/2,786.88 = 1,987.20/x
3. Step 3: Cross multiply
   2,017.92x = 2,786.88 × 1,987.20
4. Step 4: Simplify right side
   2,017.92x = 5,538,087.94
5. Step 5: Solve for x
   x = 5,538,087.94/2,017.92
6. Step 6: Final answer
   x = 2,744.45