Finding the Fourth Proportional to 1,568.22, 2,164.41 and 978.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,568.22 : 2,164.41 = 978.80 : x
2. Step 2: Convert to fraction form
   1,568.22/2,164.41 = 978.80/x
3. Step 3: Cross multiply
   1,568.22x = 2,164.41 × 978.80
4. Step 4: Simplify right side
   1,568.22x = 2,118,524.51
5. Step 5: Solve for x
   x = 2,118,524.51/1,568.22
6. Step 6: Final answer
   x = 1,350.91