Finding the Fourth Proportional to 2,085.69, 2,878.61 and 1,289.11

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.69 : 2,878.61 = 1,289.11 : x
2. Step 2: Convert to fraction form
   2,085.69/2,878.61 = 1,289.11/x
3. Step 3: Cross multiply
   2,085.69x = 2,878.61 × 1,289.11
4. Step 4: Simplify right side
   2,085.69x = 3,710,840.96
5. Step 5: Solve for x
   x = 3,710,840.96/2,085.69
6. Step 6: Final answer
   x = 1,779.19