Finding the Fourth Proportional to 2,185.86, 3,279.24 and 1,209.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,185.86 : 3,279.24 = 1,209.91 : x
2. Step 2: Convert to fraction form
   2,185.86/3,279.24 = 1,209.91/x
3. Step 3: Cross multiply
   2,185.86x = 3,279.24 × 1,209.91
4. Step 4: Simplify right side
   2,185.86x = 3,967,585.27
5. Step 5: Solve for x
   x = 3,967,585.27/2,185.86
6. Step 6: Final answer
   x = 1,815.11