Finding the Fourth Proportional to 1,388.78, 1,916.38 and 829.14

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.78 : 1,916.38 = 829.14 : x
2. Step 2: Convert to fraction form
   1,388.78/1,916.38 = 829.14/x
3. Step 3: Cross multiply
   1,388.78x = 1,916.38 × 829.14
4. Step 4: Simplify right side
   1,388.78x = 1,588,947.31
5. Step 5: Solve for x
   x = 1,588,947.31/1,388.78
6. Step 6: Final answer
   x = 1,144.13