Finding the Fourth Proportional to 1,389.30, 1,915.96 and 1,074.08

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.30 : 1,915.96 = 1,074.08 : x
2. Step 2: Convert to fraction form
   1,389.30/1,915.96 = 1,074.08/x
3. Step 3: Cross multiply
   1,389.30x = 1,915.96 × 1,074.08
4. Step 4: Simplify right side
   1,389.30x = 2,057,894.32
5. Step 5: Solve for x
   x = 2,057,894.32/1,389.30
6. Step 6: Final answer
   x = 1,481.25