Finding the Fourth Proportional to 2,335.16, 3,222.56 and 1,287.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,335.16 : 3,222.56 = 1,287.20 : x
2. Step 2: Convert to fraction form
   2,335.16/3,222.56 = 1,287.20/x
3. Step 3: Cross multiply
   2,335.16x = 3,222.56 × 1,287.20
4. Step 4: Simplify right side
   2,335.16x = 4,148,079.23
5. Step 5: Solve for x
   x = 4,148,079.23/2,335.16
6. Step 6: Final answer
   x = 1,776.36