Finding the Fourth Proportional to 1,389.62, 1,916.77 and 829.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.62 : 1,916.77 = 829.72 : x
2. Step 2: Convert to fraction form
   1,389.62/1,916.77 = 829.72/x
3. Step 3: Cross multiply
   1,389.62x = 1,916.77 × 829.72
4. Step 4: Simplify right side
   1,389.62x = 1,590,368.67
5. Step 5: Solve for x
   x = 1,590,368.67/1,389.62
6. Step 6: Final answer
   x = 1,144.46