Finding the Fourth Proportional to 1,680.78, 2,319.46 and 934.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,680.78 : 2,319.46 = 934.69 : x
2. Step 2: Convert to fraction form
   1,680.78/2,319.46 = 934.69/x
3. Step 3: Cross multiply
   1,680.78x = 2,319.46 × 934.69
4. Step 4: Simplify right side
   1,680.78x = 2,167,973.73
5. Step 5: Solve for x
   x = 2,167,973.73/1,680.78
6. Step 6: Final answer
   x = 1,289.87