Finding the Fourth Proportional to 1,389.63, 1,916.82 and 829.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.63 : 1,916.82 = 829.71 : x
2. Step 2: Convert to fraction form
   1,389.63/1,916.82 = 829.71/x
3. Step 3: Cross multiply
   1,389.63x = 1,916.82 × 829.71
4. Step 4: Simplify right side
   1,389.63x = 1,590,404.72
5. Step 5: Solve for x
   x = 1,590,404.72/1,389.63
6. Step 6: Final answer
   x = 1,144.48