Finding the Fourth Proportional to 1,017.71, 1,528.85 and 879.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,017.71 : 1,528.85 = 879.31 : x
2. Step 2: Convert to fraction form
   1,017.71/1,528.85 = 879.31/x
3. Step 3: Cross multiply
   1,017.71x = 1,528.85 × 879.31
4. Step 4: Simplify right side
   1,017.71x = 1,344,333.09
5. Step 5: Solve for x
   x = 1,344,333.09/1,017.71
6. Step 6: Final answer
   x = 1,320.94