Finding the Fourth Proportional to 1,389.04, 1,915.14 and 1,015.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.04 : 1,915.14 = 1,015.72 : x
2. Step 2: Convert to fraction form
   1,389.04/1,915.14 = 1,015.72/x
3. Step 3: Cross multiply
   1,389.04x = 1,915.14 × 1,015.72
4. Step 4: Simplify right side
   1,389.04x = 1,945,246.00
5. Step 5: Solve for x
   x = 1,945,246.00/1,389.04
6. Step 6: Final answer
   x = 1,400.42