Question

If the standard deviation of a data set was originally 5, and if each value in the data set was multiplied by 4.8, what would be the standard deviation of the resulting data?
a. 5
b. 19
c. 24
d. 14

Answer 1

Using the basic properties of variance

https://en.wikipedia.org/wiki/Variance#Basic_properties

$$
var(ax)=a^2var(x)
$$
then
$$
std(ax)=\sqrt{var(ax)}=\sqrt{a^2var(x)}=a\sqrt{var(x)}=a\times std(x)
$$
So we have that
$$
std(4.8x)=4.8\times std(x)=4.8\times 5
$$
Make sense?

Answer 2

yes

Answer 3

its c