Finding the Fourth Proportional to 1,687.75, 2,328.72 and 979.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.75 : 2,328.72 = 979.18 : x
2. Step 2: Convert to fraction form
   1,687.75/2,328.72 = 979.18/x
3. Step 3: Cross multiply
   1,687.75x = 2,328.72 × 979.18
4. Step 4: Simplify right side
   1,687.75x = 2,280,227.50
5. Step 5: Solve for x
   x = 2,280,227.50/1,687.75
6. Step 6: Final answer
   x = 1,351.05