Finding the Fourth Proportional to 1,521.16, 2,100.60 and 1,439.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,521.16 : 2,100.60 = 1,439.32 : x
2. Step 2: Convert to fraction form
   1,521.16/2,100.60 = 1,439.32/x
3. Step 3: Cross multiply
   1,521.16x = 2,100.60 × 1,439.32
4. Step 4: Simplify right side
   1,521.16x = 3,023,435.59
5. Step 5: Solve for x
   x = 3,023,435.59/1,521.16
6. Step 6: Final answer
   x = 1,987.59