Finding the Fourth Proportional to 1,288.17, 1,776.33 and 764.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.17 : 1,776.33 = 764.10 : x
2. Step 2: Convert to fraction form
   1,288.17/1,776.33 = 764.10/x
3. Step 3: Cross multiply
   1,288.17x = 1,776.33 × 764.10
4. Step 4: Simplify right side
   1,288.17x = 1,357,293.75
5. Step 5: Solve for x
   x = 1,357,293.75/1,288.17
6. Step 6: Final answer
   x = 1,053.66