Finding the Fourth Proportional to 1,764.72, 2,435.28 and 978.80

Step by Step Solution

1. Step 1: Write the proportion equation
   1,764.72 : 2,435.28 = 978.80 : x
2. Step 2: Convert to fraction form
   1,764.72/2,435.28 = 978.80/x
3. Step 3: Cross multiply
   1,764.72x = 2,435.28 × 978.80
4. Step 4: Simplify right side
   1,764.72x = 2,383,652.06
5. Step 5: Solve for x
   x = 2,383,652.06/1,764.72
6. Step 6: Final answer
   x = 1,350.73