Finding the Fourth Proportional to 2,987.28, 4,487.94 and 2,821.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,987.28 : 4,487.94 = 2,821.50 : x
2. Step 2: Convert to fraction form
   2,987.28/4,487.94 = 2,821.50/x
3. Step 3: Cross multiply
   2,987.28x = 4,487.94 × 2,821.50
4. Step 4: Simplify right side
   2,987.28x = 12,662,722.71
5. Step 5: Solve for x
   x = 12,662,722.71/2,987.28
6. Step 6: Final answer
   x = 4,238.88