Finding the Fourth Proportional to 1,438.32, 1,984.92 and 878.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.32 : 1,984.92 = 878.72 : x
2. Step 2: Convert to fraction form
   1,438.32/1,984.92 = 878.72/x
3. Step 3: Cross multiply
   1,438.32x = 1,984.92 × 878.72
4. Step 4: Simplify right side
   1,438.32x = 1,744,188.90
5. Step 5: Solve for x
   x = 1,744,188.90/1,438.32
6. Step 6: Final answer
   x = 1,212.66