Finding the Fourth Proportional to 1,408.16, 1,943.28 and 778.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,408.16 : 1,943.28 = 778.72 : x
2. Step 2: Convert to fraction form
   1,408.16/1,943.28 = 778.72/x
3. Step 3: Cross multiply
   1,408.16x = 1,943.28 × 778.72
4. Step 4: Simplify right side
   1,408.16x = 1,513,271.00
5. Step 5: Solve for x
   x = 1,513,271.00/1,408.16
6. Step 6: Final answer
   x = 1,074.64