Finding the Fourth Proportional to 1,920.69, 2,881.47 and 688.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,920.69 : 2,881.47 = 688.23 : x
2. Step 2: Convert to fraction form
   1,920.69/2,881.47 = 688.23/x
3. Step 3: Cross multiply
   1,920.69x = 2,881.47 × 688.23
4. Step 4: Simplify right side
   1,920.69x = 1,983,114.10
5. Step 5: Solve for x
   x = 1,983,114.10/1,920.69
6. Step 6: Final answer
   x = 1,032.50