Finding the Fourth Proportional to 2,219.16, 3,328.72 and 987.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,219.16 : 3,328.72 = 987.12 : x
2. Step 2: Convert to fraction form
   2,219.16/3,328.72 = 987.12/x
3. Step 3: Cross multiply
   2,219.16x = 3,328.72 × 987.12
4. Step 4: Simplify right side
   2,219.16x = 3,285,846.09
5. Step 5: Solve for x
   x = 3,285,846.09/2,219.16
6. Step 6: Final answer
   x = 1,480.67