Finding the Fourth Proportional to 1,438.17, 1,984.86 and 878.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,438.17 : 1,984.86 = 878.52 : x
2. Step 2: Convert to fraction form
   1,438.17/1,984.86 = 878.52/x
3. Step 3: Cross multiply
   1,438.17x = 1,984.86 × 878.52
4. Step 4: Simplify right side
   1,438.17x = 1,743,724.89
5. Step 5: Solve for x
   x = 1,743,724.89/1,438.17
6. Step 6: Final answer
   x = 1,212.47