Finding the Fourth Proportional to 1,636.69, 2,258.59 and 890.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.69 : 2,258.59 = 890.63 : x
2. Step 2: Convert to fraction form
   1,636.69/2,258.59 = 890.63/x
3. Step 3: Cross multiply
   1,636.69x = 2,258.59 × 890.63
4. Step 4: Simplify right side
   1,636.69x = 2,011,579.01
5. Step 5: Solve for x
   x = 2,011,579.01/1,636.69
6. Step 6: Final answer
   x = 1,229.05