Suppose that 30% of all students who have to buy a text for a particular course want a newcopy (the successes), whereas the other 70% want a used copy. Consider randomly selecting 25purchasers.(a)[3 pts]Find the mean and standard deviation of the number of students who want a newcopy of the book.

We know that 30% of all students who have to buy a text for a particular course want a newcopy, whereas the other 70% want a used copy. So, we get that:

p=30%=0.3

q=70%=0.7

n=25.

We calculate the mean:

[tex]\mu=E(X)=n\cdot p=25\cdot 0.3=7.5[/tex]

We calculate the standard deviation:

[tex]\sigma=\sqrt{p\cdot q\cdot n}=\sqrt{0.3\cdot 0.7\cdot 25}=\sqrt{5.25}=2.3\\[/tex]

We get that the mean and standard deviation are:

[tex]\mu=7.5\\\\\sigma=2.3\\[/tex]