Finding the Fourth Proportional to 2,557.89, 3,837.78 and 998.64

Step by Step Solution

1. Step 1: Write the proportion equation
   2,557.89 : 3,837.78 = 998.64 : x
2. Step 2: Convert to fraction form
   2,557.89/3,837.78 = 998.64/x
3. Step 3: Cross multiply
   2,557.89x = 3,837.78 × 998.64
4. Step 4: Simplify right side
   2,557.89x = 3,832,560.62
5. Step 5: Solve for x
   x = 3,832,560.62/2,557.89
6. Step 6: Final answer
   x = 1,498.33