Finding the Fourth Proportional to 1,383.30, 1,908.86 and 823.81

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.30 : 1,908.86 = 823.81 : x
2. Step 2: Convert to fraction form
   1,383.30/1,908.86 = 823.81/x
3. Step 3: Cross multiply
   1,383.30x = 1,908.86 × 823.81
4. Step 4: Simplify right side
   1,383.30x = 1,572,537.96
5. Step 5: Solve for x
   x = 1,572,537.96/1,383.30
6. Step 6: Final answer
   x = 1,136.80