Answer:

Step-by-step explanation:
The confidence interval for the population mean x can be calculated as:

Where x' is the sample mean, s is the population standard deviation, n is the sample size and
is the z-score that let a proportion of
on the right tail.
is calculated as: 100%-99%=1%
So, 
Finally, replacing the values of x' by 308, s by 17, n by 15 and
by 2.576, we get that the confidence interval is:

Answer:
your a very beautiful dumb.asss
Step-by-step explanation:
go give your self a bj
I don’t know but I’m not gonna say anything so you don’t get it wrong
Answer:
(a) 3 - 2x - 2x² (b) -21
Step-by-step explanation:
given, y +2x² = 3 -2x
make y the subject:
y = 3 - 2x - 2x²
if y = f(x)
then
f(x) = 3 - 2x - 2x²
(b)<u> to find f(3) we need to replace x with 3:</u>
<u />
3 - 2(3) - 2*(3)²
-21