Finding the Fourth Proportional to 2,642.16, 3,962.78 and 998.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,642.16 : 3,962.78 = 998.72 : x
2. Step 2: Convert to fraction form
   2,642.16/3,962.78 = 998.72/x
3. Step 3: Cross multiply
   2,642.16x = 3,962.78 × 998.72
4. Step 4: Simplify right side
   2,642.16x = 3,957,707.64
5. Step 5: Solve for x
   x = 3,957,707.64/2,642.16
6. Step 6: Final answer
   x = 1,497.91