Finding the Fourth Proportional to 2,642.18, 3,963.38 and 998.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,642.18 : 3,963.38 = 998.70 : x
2. Step 2: Convert to fraction form
   2,642.18/3,963.38 = 998.70/x
3. Step 3: Cross multiply
   2,642.18x = 3,963.38 × 998.70
4. Step 4: Simplify right side
   2,642.18x = 3,958,227.61
5. Step 5: Solve for x
   x = 3,958,227.61/2,642.18
6. Step 6: Final answer
   x = 1,498.09