Finding the Fourth Proportional to 1,017.79, 1,404.50 and 685.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.79 : 1,404.50 = 685.69 : x
2. Step 2: Convert to fraction form
   1,017.79/1,404.50 = 685.69/x
3. Step 3: Cross multiply
   1,017.79x = 1,404.50 × 685.69
4. Step 4: Simplify right side
   1,017.79x = 963,044.67
5. Step 5: Solve for x
   x = 963,044.67/1,017.79
6. Step 6: Final answer
   x = 946.21