Finding the Fourth Proportional to 7,806.88, 10,780.72 and 5,017.28

Step by Step Solution

1. Step 1: Write the proportion equation
   7,806.88 : 10,780.72 = 5,017.28 : x
2. Step 2: Convert to fraction form
   7,806.88/10,780.72 = 5,017.28/x
3. Step 3: Cross multiply
   7,806.88x = 10,780.72 × 5,017.28
4. Step 4: Simplify right side
   7,806.88x = 54,089,890.84
5. Step 5: Solve for x
   x = 54,089,890.84/7,806.88
6. Step 6: Final answer
   x = 6,928.49