Finding the Fourth Proportional to 1,240.30, 1,856.80 and 828.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,240.30 : 1,856.80 = 828.42 : x
2. Step 2: Convert to fraction form
   1,240.30/1,856.80 = 828.42/x
3. Step 3: Cross multiply
   1,240.30x = 1,856.80 × 828.42
4. Step 4: Simplify right side
   1,240.30x = 1,538,196.83
5. Step 5: Solve for x
   x = 1,538,196.83/1,240.30
6. Step 6: Final answer
   x = 1,240.18