Finding the Fourth Proportional to 2,647, 3,971.94 and 1,279

Step by Step Solution

1. Step 1: Write the proportion equation
   2,647 : 3,971.94 = 1,279 : x
2. Step 2: Convert to fraction form
   2,647/3,971.94 = 1,279/x
3. Step 3: Cross multiply
   2,647x = 3,971.94 × 1,279
4. Step 4: Simplify right side
   2,647x = 5,080,111.26
5. Step 5: Solve for x
   x = 5,080,111.26/2,647
6. Step 6: Final answer
   x = 1,919.20