Finding the Fourth Proportional to 1,343.34, 1,854.72 and 878.40

Step by Step Solution

1. Step 1: Write the proportion equation
   1,343.34 : 1,854.72 = 878.40 : x
2. Step 2: Convert to fraction form
   1,343.34/1,854.72 = 878.40/x
3. Step 3: Cross multiply
   1,343.34x = 1,854.72 × 878.40
4. Step 4: Simplify right side
   1,343.34x = 1,629,186.05
5. Step 5: Solve for x
   x = 1,629,186.05/1,343.34
6. Step 6: Final answer
   x = 1,212.79