Finding the Fourth Proportional to 1,636.42, 2,258.30 and 890.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.42 : 2,258.30 = 890.38 : x
2. Step 2: Convert to fraction form
   1,636.42/2,258.30 = 890.38/x
3. Step 3: Cross multiply
   1,636.42x = 2,258.30 × 890.38
4. Step 4: Simplify right side
   1,636.42x = 2,010,745.15
5. Step 5: Solve for x
   x = 2,010,745.15/1,636.42
6. Step 6: Final answer
   x = 1,228.75