Answer:
Required probability is 0.19
Step-by-step explanation:
The two-way table for the given data is,
Fiction Non-Fiction Total
9th grade 35 8 43
10th grade 52 12 64
Total 87 20 107
It is required to find the probability of the students who prefer to read non-fiction novels, given that they are in 9th grade.
That is, to find the conditional probability
.
Now, 
So, we get,

<h3>Thus, the required probability is 0.19.</h3>
Answer:
The answer to your questions is below
Step-by-step explanation:
4.-
In a 45°-45°-90° triangle, the length of the legs are "x" and the length of the hypotenuse is x
Then, in this problem, the length of the leg is 7 then the length of the hypotenuse will be 7
5.- In a 30°-60°-90° triangle, the length of the hypotenuse is 2x, the length of the longer leg is x
and the length of the shorter leg is x.
In this problem we have the length of the hypotenuse = 20 and find x.
2x = 20
x = 20/2
x = 10
longer leg = x
6.- nonzero
7.- hypotenuse = 20 cm
Find x
2x = 20
x = 20/2
x = 10
Shoter leg = x = 10 cm
I'll assume the usual definition of set difference,
.
Let
. Then
and
. If
, then
and
. This means
and
, so it follows that
. Hence
.
Now let
. Then
and
. By definition of set difference,
and
. Since
, we have
, and so
. Hence
.
The two sets are subsets of one another, so they must be equal.
The proof of this is the same as above, you just have to indicate that membership, of lack thereof, holds for all indices
.
Proof of one direction for example:
Let
. Then
and
, which in turn means
for all
. This means
, and
, and so on, where
, for all
. This means
, and
, and so on, so
. Hence
.
Answer:
a) Null and alternative hypothesis:

b) A Type I error is made when a true null hypothesis is rejected. In this case, it would mean a conclusion that the proportion is significantly bigger than 10%, when in fact it is not.
c) The consequences would be that they would be more optimistic than they should about the result of the investment, expecting a proportion of students that is bigger than the true population proportion.
d) A Type II error is made when a false null hypothesis is failed to be rejected. This would mean that, although the proportion is significantly bigger than 10%, there is no enough evidence and it is concluded erroneously that the proportion is not significantly bigger than 10%
e) The consequences would be that the investment may not be made, even when the results would have been more positive than expected from the conclusion of the hypothesis test.
Step-by-step explanation:
a) The hypothesis should be carried to test if the proportion of students that would eat there at least once a week is significantly higher than 10%.
Then, the alternative or spectulative hypothesis will state this claim: that the population proportion is significantly bigger than 10%.
On the contrary, the null hypothesis will state that this proportion is not significantly higher than 10%.
This can be written as:

I think it would be (1,-2)