Question

In the checksums, you validated that the average SAT score for all of the records is 1,059.07. When we work with the data more rigorously, several tests will require us to transform NULL values. If you were to transform the NULL SAT values into 0, what would happen to the average (would it stay the same, decrease, or increase?

Answer 1

It would decrease.

Explanation:

The null almost always acts like a placeholder where there is nothing to record for that entry, we can say that it is a dummy character.

The difference between null and zero is that zero has a value in a context whereas null does not have any value.

So given the example in the question, if we replace the null values with zeros, that would affect the average because of the fact that zero values are going to get included in the average, null values were not included. Therefore this will result in the average being decreased.

I hope this answer helps.