Finding the Fourth Proportional to 1,687.31, 2,328.61 and 979.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,687.31 : 2,328.61 = 979.34 : x
2. Step 2: Convert to fraction form
   1,687.31/2,328.61 = 979.34/x
3. Step 3: Cross multiply
   1,687.31x = 2,328.61 × 979.34
4. Step 4: Simplify right side
   1,687.31x = 2,280,486.83
5. Step 5: Solve for x
   x = 2,280,486.83/1,687.31
6. Step 6: Final answer
   x = 1,351.56