Finding the Fourth Proportional to 2,085.72, 2,878.34 and 1,289.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.72 : 2,878.34 = 1,289.16 : x
2. Step 2: Convert to fraction form
   2,085.72/2,878.34 = 1,289.16/x
3. Step 3: Cross multiply
   2,085.72x = 2,878.34 × 1,289.16
4. Step 4: Simplify right side
   2,085.72x = 3,710,634.35
5. Step 5: Solve for x
   x = 3,710,634.35/2,085.72
6. Step 6: Final answer
   x = 1,779.07