Finding the Fourth Proportional to 1,003.78, 1,386.95 and 828.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,003.78 : 1,386.95 = 828.82 : x
2. Step 2: Convert to fraction form
   1,003.78/1,386.95 = 828.82/x
3. Step 3: Cross multiply
   1,003.78x = 1,386.95 × 828.82
4. Step 4: Simplify right side
   1,003.78x = 1,149,520.82
5. Step 5: Solve for x
   x = 1,149,520.82/1,003.78
6. Step 6: Final answer
   x = 1,145.20