Finding the Fourth Proportional to 2,087.56, 2,879.82 and 1,290.22

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.56 : 2,879.82 = 1,290.22 : x
2. Step 2: Convert to fraction form
   2,087.56/2,879.82 = 1,290.22/x
3. Step 3: Cross multiply
   2,087.56x = 2,879.82 × 1,290.22
4. Step 4: Simplify right side
   2,087.56x = 3,715,601.36
5. Step 5: Solve for x
   x = 3,715,601.36/2,087.56
6. Step 6: Final answer
   x = 1,779.88