Finding the Fourth Proportional to 1,288.89, 1,779.00 and 817.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.89 : 1,779.00 = 817.07 : x
2. Step 2: Convert to fraction form
   1,288.89/1,779.00 = 817.07/x
3. Step 3: Cross multiply
   1,288.89x = 1,779.00 × 817.07
4. Step 4: Simplify right side
   1,288.89x = 1,453,555.57
5. Step 5: Solve for x
   x = 1,453,555.57/1,288.89
6. Step 6: Final answer
   x = 1,127.76