Finding the Fourth Proportional to 1,679.10, 2,518.56 and 857.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,679.10 : 2,518.56 = 857.34 : x
2. Step 2: Convert to fraction form
   1,679.10/2,518.56 = 857.34/x
3. Step 3: Cross multiply
   1,679.10x = 2,518.56 × 857.34
4. Step 4: Simplify right side
   1,679.10x = 2,159,262.23
5. Step 5: Solve for x
   x = 2,159,262.23/1,679.10
6. Step 6: Final answer
   x = 1,285.96