Finding the Fourth Proportional to 2,570.39, 3,855.60 and 925.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,570.39 : 3,855.60 = 925.78 : x
2. Step 2: Convert to fraction form
   2,570.39/3,855.60 = 925.78/x
3. Step 3: Cross multiply
   2,570.39x = 3,855.60 × 925.78
4. Step 4: Simplify right side
   2,570.39x = 3,569,437.37
5. Step 5: Solve for x
   x = 3,569,437.37/2,570.39
6. Step 6: Final answer
   x = 1,388.68