Finding the Fourth Proportional to 1,388.02, 1,914.90 and 828.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.02 : 1,914.90 = 828.37 : x
2. Step 2: Convert to fraction form
   1,388.02/1,914.90 = 828.37/x
3. Step 3: Cross multiply
   1,388.02x = 1,914.90 × 828.37
4. Step 4: Simplify right side
   1,388.02x = 1,586,245.71
5. Step 5: Solve for x
   x = 1,586,245.71/1,388.02
6. Step 6: Final answer
   x = 1,142.81