Finding the Fourth Proportional to 2,807.78, 4,212.32 and 958.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,807.78 : 4,212.32 = 958.91 : x
2. Step 2: Convert to fraction form
   2,807.78/4,212.32 = 958.91/x
3. Step 3: Cross multiply
   2,807.78x = 4,212.32 × 958.91
4. Step 4: Simplify right side
   2,807.78x = 4,039,209.92
5. Step 5: Solve for x
   x = 4,039,209.92/2,807.78
6. Step 6: Final answer
   x = 1,438.58