Finding the Fourth Proportional to 1,636.40, 2,258.18 and 890.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.40 : 2,258.18 = 890.34 : x
2. Step 2: Convert to fraction form
   1,636.40/2,258.18 = 890.34/x
3. Step 3: Cross multiply
   1,636.40x = 2,258.18 × 890.34
4. Step 4: Simplify right side
   1,636.40x = 2,010,543.53
5. Step 5: Solve for x
   x = 2,010,543.53/1,636.40
6. Step 6: Final answer
   x = 1,228.64