Finding the Fourth Proportional to 2,111.20, 3,166.54 and 878.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.20 : 3,166.54 = 878.76 : x
2. Step 2: Convert to fraction form
   2,111.20/3,166.54 = 878.76/x
3. Step 3: Cross multiply
   2,111.20x = 3,166.54 × 878.76
4. Step 4: Simplify right side
   2,111.20x = 2,782,628.69
5. Step 5: Solve for x
   x = 2,782,628.69/2,111.20
6. Step 6: Final answer
   x = 1,318.03