Finding the Fourth Proportional to 2,870.72, 3,961.28 and 1,611.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,870.72 : 3,961.28 = 1,611.60 : x
2. Step 2: Convert to fraction form
   2,870.72/3,961.28 = 1,611.60/x
3. Step 3: Cross multiply
   2,870.72x = 3,961.28 × 1,611.60
4. Step 4: Simplify right side
   2,870.72x = 6,383,998.85
5. Step 5: Solve for x
   x = 6,383,998.85/2,870.72
6. Step 6: Final answer
   x = 2,223.83