Finding the Fourth Proportional to 1,870.49, 2,578.74 and 1,399.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,870.49 : 2,578.74 = 1,399.07 : x
2. Step 2: Convert to fraction form
   1,870.49/2,578.74 = 1,399.07/x
3. Step 3: Cross multiply
   1,870.49x = 2,578.74 × 1,399.07
4. Step 4: Simplify right side
   1,870.49x = 3,607,838.97
5. Step 5: Solve for x
   x = 3,607,838.97/1,870.49
6. Step 6: Final answer
   x = 1,928.82