Finding the Fourth Proportional to 1,288.54, 1,776.25 and 1,008.29

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.54 : 1,776.25 = 1,008.29 : x
2. Step 2: Convert to fraction form
   1,288.54/1,776.25 = 1,008.29/x
3. Step 3: Cross multiply
   1,288.54x = 1,776.25 × 1,008.29
4. Step 4: Simplify right side
   1,288.54x = 1,790,965.63
5. Step 5: Solve for x
   x = 1,790,965.63/1,288.54
6. Step 6: Final answer
   x = 1,389.92