Answer:
A and D
Step-by-step explanation:
4×3=12
4×d=4d
12+4d
Then;(4×d)+(3×4)=4d +12
Same expression
Answer:

And we have a sample size of n =81. We want to estimate the standard error of the sampling distribution
and for this case we know that the distribution is given by:

And the standard error would be:

And replacing we got:

Step-by-step explanation:
For this case we know the population deviation given by:

And we have a sample size of n =81. We want to estimate the standard error of the sampling distribution
and for this case we know that the distribution is given by:

And the standard error would be:

And replacing we got:

Answer:

Step-by-step explanation:
Given that f(x) is a polynomial function.
This implies that f(x) has x terms of positive integral degrees and also rational coefficients only.
Since an irrational root is given a root of f(x), we find that its conjugate also should be a root of f(x)
i.e. If
is a root, then
is also a root.
(Because this only when multiplied will make coefficients rational)
So the factors of f(x) should be atleast

There can be other factors also but this is compulsory
I cannot suggest anything other than the set of real numbers here, but maybe someone else can provide a better answer. As long as you increase or decrease x (which is a real number) then you will get a real number, or the infinite set of real numbers.