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:

Step-by-step explanation:
Quadratic function is given as 
Let's find a, b and c:
Substituting (0, 6):



Now that we know the value of c, let's derive 2 system of equations we would use to solve for a and b simultaneously as follows.
Substituting (2, 16), and c = 6








=> (Equation 1)
Substituting (3, 33), and c = 6








=> (Equation 2)
Subtract equation 1 from equation 2 to solve simultaneously for a and b.


Replace a with 4 in equation 2.
The quadratic function that represents the given 3 points would be as follows:



The unit rate for that equation is .33
Exactly 29.7, but you can't have 7/10 of a student so you round to 30. So 30 students are playing a music instrument because 330 times 0.09 is about 30