If a data set has an extreme value added in the low end of values, what is true about the sample mean?

A. It gets smaller. B. It gets larger. C. It stays the same. D. We can say nothing without a computation.

The answer given is A, but can you explain to me why it gets smaller in more detail using the formula, please?

For example, the data set used is

1, 2, 3, 4, 5, 6, 7, 8, 9 The Median is 5, Q1 is 2.5, and Q3 is 7.5.

(xi/n) = 45/9= 5

the sample mean = 5 is what I have

I solved for s the sample standard deviation and was able to see why it got larger.

but somehow I got lost with this question.