Finding the Fourth Proportional to 1,899.18, 2,618.78 and 1,392.75

Step by Step Solution

1. Step 1: Write the proportion equation
   1,899.18 : 2,618.78 = 1,392.75 : x
2. Step 2: Convert to fraction form
   1,899.18/2,618.78 = 1,392.75/x
3. Step 3: Cross multiply
   1,899.18x = 2,618.78 × 1,392.75
4. Step 4: Simplify right side
   1,899.18x = 3,647,298.88
5. Step 5: Solve for x
   x = 3,647,298.88/1,899.18
6. Step 6: Final answer
   x = 1,920.46