Finding the Fourth Proportional to 2,164.30, 2,986.72 and 1,280.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,164.30 : 2,986.72 = 1,280.09 : x
2. Step 2: Convert to fraction form
   2,164.30/2,986.72 = 1,280.09/x
3. Step 3: Cross multiply
   2,164.30x = 2,986.72 × 1,280.09
4. Step 4: Simplify right side
   2,164.30x = 3,823,265.07
5. Step 5: Solve for x
   x = 3,823,265.07/2,164.30
6. Step 6: Final answer
   x = 1,766.51