Finding the Fourth Proportional to 2,419.78, 3,339.24 and 1,315.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,419.78 : 3,339.24 = 1,315.78 : x
2. Step 2: Convert to fraction form
   2,419.78/3,339.24 = 1,315.78/x
3. Step 3: Cross multiply
   2,419.78x = 3,339.24 × 1,315.78
4. Step 4: Simplify right side
   2,419.78x = 4,393,705.21
5. Step 5: Solve for x
   x = 4,393,705.21/2,419.78
6. Step 6: Final answer
   x = 1,815.75