Finding the Fourth Proportional to 2,210.57, 3,315.09 and 978.84

Step by Step Solution

1. Step 1: Write the proportion equation
   2,210.57 : 3,315.09 = 978.84 : x
2. Step 2: Convert to fraction form
   2,210.57/3,315.09 = 978.84/x
3. Step 3: Cross multiply
   2,210.57x = 3,315.09 × 978.84
4. Step 4: Simplify right side
   2,210.57x = 3,244,947.43
5. Step 5: Solve for x
   x = 3,244,947.43/2,210.57
6. Step 6: Final answer
   x = 1,467.93