Finding the Fourth Proportional to 5,185.38, 7,778.10 and 1,289.78

Step by Step Solution

1. Step 1: Write the proportion equation
   5,185.38 : 7,778.10 = 1,289.78 : x
2. Step 2: Convert to fraction form
   5,185.38/7,778.10 = 1,289.78/x
3. Step 3: Cross multiply
   5,185.38x = 7,778.10 × 1,289.78
4. Step 4: Simplify right side
   5,185.38x = 10,032,031.37
5. Step 5: Solve for x
   x = 10,032,031.37/5,185.38
6. Step 6: Final answer
   x = 1,934.68