Finding the Fourth Proportional to 2,858.78, 4,289.38 and 1,298.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,858.78 : 4,289.38 = 1,298.72 : x
2. Step 2: Convert to fraction form
   2,858.78/4,289.38 = 1,298.72/x
3. Step 3: Cross multiply
   2,858.78x = 4,289.38 × 1,298.72
4. Step 4: Simplify right side
   2,858.78x = 5,570,703.59
5. Step 5: Solve for x
   x = 5,570,703.59/2,858.78
6. Step 6: Final answer
   x = 1,948.63