Finding the Fourth Proportional to 2,111.56, 3,166.67 and 878.65

Step by Step Solution

1. Step 1: Write the proportion equation
   2,111.56 : 3,166.67 = 878.65 : x
2. Step 2: Convert to fraction form
   2,111.56/3,166.67 = 878.65/x
3. Step 3: Cross multiply
   2,111.56x = 3,166.67 × 878.65
4. Step 4: Simplify right side
   2,111.56x = 2,782,388.88
5. Step 5: Solve for x
   x = 2,782,388.88/2,111.56
6. Step 6: Final answer
   x = 1,317.70