Finding the Fourth Proportional to 1,397.72, 1,931.36 and 1,004.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.72 : 1,931.36 = 1,004.06 : x
2. Step 2: Convert to fraction form
   1,397.72/1,931.36 = 1,004.06/x
3. Step 3: Cross multiply
   1,397.72x = 1,931.36 × 1,004.06
4. Step 4: Simplify right side
   1,397.72x = 1,939,201.32
5. Step 5: Solve for x
   x = 1,939,201.32/1,397.72
6. Step 6: Final answer
   x = 1,387.40