Finding the Fourth Proportional to 1,389.24, 1,917.06 and 829.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.24 : 1,917.06 = 829.89 : x
2. Step 2: Convert to fraction form
   1,389.24/1,917.06 = 829.89/x
3. Step 3: Cross multiply
   1,389.24x = 1,917.06 × 829.89
4. Step 4: Simplify right side
   1,389.24x = 1,590,948.92
5. Step 5: Solve for x
   x = 1,590,948.92/1,389.24
6. Step 6: Final answer
   x = 1,145.19