Finding the Fourth Proportional to 1,397.73, 1,928.01 and 1,005.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,397.73 : 1,928.01 = 1,005.28 : x
2. Step 2: Convert to fraction form
   1,397.73/1,928.01 = 1,005.28/x
3. Step 3: Cross multiply
   1,397.73x = 1,928.01 × 1,005.28
4. Step 4: Simplify right side
   1,397.73x = 1,938,189.89
5. Step 5: Solve for x
   x = 1,938,189.89/1,397.73
6. Step 6: Final answer
   x = 1,386.67