Answer:
A
Step-by-step explanation:
Joint variation is given by:

Where k is some constant.
We are given that y = 360 when x = 4 and z = 10. Therefore:

Solving for k:

Therefore, our equation is:

Then when x = 5 and z = 12:

The answer is A.
Let
be the random variable for the number of marks a given student receives on the exam.
10% of students obtain more than 75 marks, so

where
follows a standard normal distribution. The critical value for an upper-tail probability of 10% is

where
denotes the CDF of
, and
denotes the inverse CDF. We have

Similarly, because 20% of students obtain less than 40 marks, we have

so that

Then
are such that


and we find

Answer:
x ∈ [-2, 7]
Step-by-step explanation:
The given equation ...
x^2 -5x -4 ≤ 10
can be rewritten as ...
x^2 -5x -14 ≤ 0
and factored as ...
(x +2)(x -7) ≤ 0
Clearly, the "or equal to" condition will be met when x=-2 and x=7. For values of x between these numbers, one factor is negative and the other is positive. Hence the product will be negative. So, numbers in that interval are the solution set.
x ∈ [-2, 7]
Yes he is correct because if you do the algorithm, 0+3=3 and 20+40=60 and 60+3=63. There is no regrouping needed.
Brian should purchase Choice C of fabric
<em><u>Solution:</u></em>
Given that Brian wants to purchase a piece of fabric that is between 49 and 53 inches long
So piece of fabric should be between: 49 and 53 inches
- Choice A is
feet long
Let us convert feet to inches

Now convert to inches
We know that,
1 feet = 12 inches

But this choice is greater than given condition that piece of fabric should be between: 49 and 53 inches
So this is not correct
- Choice B is
feet long

Now convert to inches

But this choice is greater than given condition that piece of fabric should be between: 49 and 53 inches
So this is not correct
- Choice C is
feet long

Now convert to inches

So this 52 inches lies between 49 and 53 inches
So Brian should purchase Choice C of fabric