Finding the Fourth Proportional to 1,689.53, 2,532.81 and 811.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,689.53 : 2,532.81 = 811.59 : x
2. Step 2: Convert to fraction form
   1,689.53/2,532.81 = 811.59/x
3. Step 3: Cross multiply
   1,689.53x = 2,532.81 × 811.59
4. Step 4: Simplify right side
   1,689.53x = 2,055,603.27
5. Step 5: Solve for x
   x = 2,055,603.27/1,689.53
6. Step 6: Final answer
   x = 1,216.68