Finding the Fourth Proportional to 1,388.79, 1,916.53 and 759.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,388.79 : 1,916.53 = 759.31 : x
2. Step 2: Convert to fraction form
   1,388.79/1,916.53 = 759.31/x
3. Step 3: Cross multiply
   1,388.79x = 1,916.53 × 759.31
4. Step 4: Simplify right side
   1,388.79x = 1,455,236.55
5. Step 5: Solve for x
   x = 1,455,236.55/1,388.79
6. Step 6: Final answer
   x = 1,047.84