Finding the Fourth Proportional to 7,800.42, 10,778.32 and 5,780.94

Step by Step Solution

1. Step 1: Write the proportion equation
   7,800.42 : 10,778.32 = 5,780.94 : x
2. Step 2: Convert to fraction form
   7,800.42/10,778.32 = 5,780.94/x
3. Step 3: Cross multiply
   7,800.42x = 10,778.32 × 5,780.94
4. Step 4: Simplify right side
   7,800.42x = 62,308,821.22
5. Step 5: Solve for x
   x = 62,308,821.22/7,800.42
6. Step 6: Final answer
   x = 7,987.88