Exam PL-300 topic 2 question 86 discussion

D is the correct answer. Removing rows is not the solution. Item Quantity is always present. Replace Freight Amount with 0 if it is null

Won't replacing null values with zero bring down the average freight amount? That wouldn't be an accurate average of the freight amounts when rows with no data are still included. Unless the client would be okay with that,

A. is "...always populated...:" so no need o replace any null value B. removing rows with null values would also remove information from other columns that are required for the report C. similar to previous, we cannot remove any column without losing needed information D. to calculate averages, we need to replace ull values with 0

Replace the nulls with 0's in the Freight Amount column

I agree with the response. However, If replacing null values by zero for freight amounts is correct, I suppose that replacing null values by zero for Tax amount would be correct, as well. To have a more complete response, why not considering also this option?

Svp pourquoi D serait vrai et pas A?

D is the answer

Need to get rid of nulls so we can aggregate

From my point of view, no option is correct! Why? Because the "freight Amount" column is the problem. If this column has no values for all rows, so it can have "null" values, it is not recommended to create a visualization where we use the AVERAGE operation for this column (the sum will always be ok, but the number by which it is divided is not correct, taking into account null values it will be higher and we will never obtain a correct average ). A similar question was in the documentation for the preparation of this exam. Also, we can't remove the rows that contain null values based on "Freight Amount" column, because the deleted rows will contain information for the other columns that are used in the analysis and we won't get real and correct results in their analysis.