Finding the Fourth Proportional to 1,636.80, 2,258.91 and 928.77

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.80 : 2,258.91 = 928.77 : x
2. Step 2: Convert to fraction form
   1,636.80/2,258.91 = 928.77/x
3. Step 3: Cross multiply
   1,636.80x = 2,258.91 × 928.77
4. Step 4: Simplify right side
   1,636.80x = 2,097,996.10
5. Step 5: Solve for x
   x = 2,097,996.10/1,636.80
6. Step 6: Final answer
   x = 1,281.77