Finding the Fourth Proportional to 1,428.38, 1,971.43 and 807.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,428.38 : 1,971.43 = 807.38 : x
2. Step 2: Convert to fraction form
   1,428.38/1,971.43 = 807.38/x
3. Step 3: Cross multiply
   1,428.38x = 1,971.43 × 807.38
4. Step 4: Simplify right side
   1,428.38x = 1,591,681.28
5. Step 5: Solve for x
   x = 1,591,681.28/1,428.38
6. Step 6: Final answer
   x = 1,114.33