Answer: 6630
Step-by-step explanation:
Given , Number of documentaries = 17
Number of children's movies = 20
Total movies = 17+20=37
Number of combinations of r things taken out of things = 
Now, the number of different combinations of 3 movies can she rent if she wants at least one documentary
= (1 documentary+2 children's movies , 2 documentary+1 children's movies , 3 documentary+0 children's movies)


Hence, the number of different combinations of 3 movies can she rent if she wants at least one documentary is 6630 .
You made a mistake with the probability
, which should be
in the last expression, so to be clear I will state the expression again.
So we want to solve the following:
Conditioned on this event, show that the probability that her paper is in drawer
, is given by:
(1)
and
(2) 
so we can say:
is the event that you search drawer
and find nothing,
is the event that you search drawer
and find the paper,
is the event that the paper is in drawer 
this gives us:


Solution to Part (1):
if
, then
,
this means that

as needed so part one is solved.
Solution to Part(2):
so we have now that if
=
, we get that:

remember that:

this implies that:

so we just need to combine the above relations to get:

as needed so part two is solved.
Answer: (15.47, 24.53)
Step-by-step explanation:
We know that the confidence interval for population mean is given by :_

, where n= sample size.
= standard deviation.
= sample mean.
z*= Critical value.
Given : n= 450


Critical value for 95% confidence = z*=1.96 [From z-value table]
Then, the 95% confidence interval will be :-




Hence, the 95% confidence interval for the mean change in score μ μ in the population of all high school seniors. : (15.47, 24.53)
21/2 is what you should get if you divide those two
Answer:

Step-by-step explanation:
3p + 4r = q
3p = q - 4r
