Finding the Fourth Proportional to 2,141.71, 3,212.78 and 842.88

Step by Step Solution

1. Step 1: Write the proportion equation
   2,141.71 : 3,212.78 = 842.88 : x
2. Step 2: Convert to fraction form
   2,141.71/3,212.78 = 842.88/x
3. Step 3: Cross multiply
   2,141.71x = 3,212.78 × 842.88
4. Step 4: Simplify right side
   2,141.71x = 2,707,988.01
5. Step 5: Solve for x
   x = 2,707,988.01/2,141.71
6. Step 6: Final answer
   x = 1,264.40