Finding the Fourth Proportional to 2,111.34, 3,167.04 and 878.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.34 : 3,167.04 = 878.40 : x
2. Step 2: Convert to fraction form
   2,111.34/3,167.04 = 878.40/x
3. Step 3: Cross multiply
   2,111.34x = 3,167.04 × 878.40
4. Step 4: Simplify right side
   2,111.34x = 2,781,927.94
5. Step 5: Solve for x
   x = 2,781,927.94/2,111.34
6. Step 6: Final answer
   x = 1,317.61