Finding the Fourth Proportional to 1,686.75, 2,327.71 and 978.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,686.75 : 2,327.71 = 978.73 : x
2. Step 2: Convert to fraction form
   1,686.75/2,327.71 = 978.73/x
3. Step 3: Cross multiply
   1,686.75x = 2,327.71 × 978.73
4. Step 4: Simplify right side
   1,686.75x = 2,278,199.61
5. Step 5: Solve for x
   x = 2,278,199.61/1,686.75
6. Step 6: Final answer
   x = 1,350.64