Finding the Fourth Proportional to 2,111.81, 3,164.46 and 878.18

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.81 : 3,164.46 = 878.18 : x
2. Step 2: Convert to fraction form
   2,111.81/3,164.46 = 878.18/x
3. Step 3: Cross multiply
   2,111.81x = 3,164.46 × 878.18
4. Step 4: Simplify right side
   2,111.81x = 2,778,965.48
5. Step 5: Solve for x
   x = 2,778,965.48/2,111.81
6. Step 6: Final answer
   x = 1,315.92