Finding the Fourth Proportional to 1,087.78, 1,500.12 and 838.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.78 : 1,500.12 = 838.71 : x
2. Step 2: Convert to fraction form
   1,087.78/1,500.12 = 838.71/x
3. Step 3: Cross multiply
   1,087.78x = 1,500.12 × 838.71
4. Step 4: Simplify right side
   1,087.78x = 1,258,161.89
5. Step 5: Solve for x
   x = 1,258,161.89/1,087.78
6. Step 6: Final answer
   x = 1,156.63