Finding the Fourth Proportional to 1,383.69, 1,908.51 and 823.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,383.69 : 1,908.51 = 823.72 : x
2. Step 2: Convert to fraction form
   1,383.69/1,908.51 = 823.72/x
3. Step 3: Cross multiply
   1,383.69x = 1,908.51 × 823.72
4. Step 4: Simplify right side
   1,383.69x = 1,572,080.24
5. Step 5: Solve for x
   x = 1,572,080.24/1,383.69
6. Step 6: Final answer
   x = 1,136.15