Finding the Fourth Proportional to 1,636.47, 2,258.34 and 890.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.47 : 2,258.34 = 890.43 : x
2. Step 2: Convert to fraction form
   1,636.47/2,258.34 = 890.43/x
3. Step 3: Cross multiply
   1,636.47x = 2,258.34 × 890.43
4. Step 4: Simplify right side
   1,636.47x = 2,010,893.69
5. Step 5: Solve for x
   x = 2,010,893.69/1,636.47
6. Step 6: Final answer
   x = 1,228.80