Answer:
We need to sample at least 37 weeks of data.
Step-by-step explanation:
We have that to find our 
level, that is the subtraction of 1 by the confidence interval divided by 2. So:
Now, we have to find z in the Ztable as such z has a pvalue of 
.
So it is z with a pvalue of 
, so 
Now, find the margin of error M as such
We want 98% confidence that the sample mean is within $500 of the population mean, and the population standard deviation is known to be $1300
This is at least n weeks, in which n is found when 
So
Rounding up
We need to sample at least 37 weeks of data.
It's a bit of a bummer to have to work through all of these to find the answer. That a lot of slope calculations (or graphing, or whatever). When there are this many, a spreadsheet or other machine help can make it easier.
The correct choice is the last one, XYZ, with vertex X being where the right angle is located.
_____
Slope of XY is 4/7; slope of XZ is -7/4. The product of these is -1, so those segments are at right angles.
Answer: x = 2921, y = 579
Step-by-Step Explanation:
I am assuming that we just have to Solve for ‘x’ and ‘y’.
‘x’ = No. Of Contemporary Titles
‘y’ = No. Of Classic Titles
=> x + y = 3500 (Eq. 1)
=> x - y = 2342 (Eq. 2)
Adding Eq. 1 and Eq. 2, we get :-
2x = 3500 + 2342
2x = 5842
x = 5842/2
=> x = 2921
Therefore, x = 2921
Substitute value of ‘x’ in Eq. 1 :-
x + y = 3500
(2921) + y = 3500
y = 3500 - 2921
=> y = 579
Therefore, y = 579
Hence,
No. Of Contemporary Titles = 2921
No. Of Classic Titles = 579
The solution to the system of equations x + 2y = 1 and -3x-2y = 5 is:
x = -3, y = 2
The given system of equations:
x + 2y = 1............(1)
-3x - 2y = 5..........(2)
This can be written in matrix form as shown:
![\left[\begin{array}{ccc}1&2\\-3&-2\end{array}\right] \left[\begin{array}{ccc}x\\y\end{array}\right] = \left[\begin{array}{ccc}1\\5\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%5C%5C-3%26-2%5Cend%7Barray%7D%5Cright%5D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Dx%5C%5Cy%5Cend%7Barray%7D%5Cright%5D%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%5C%5C5%5Cend%7Barray%7D%5Cright%5D)
Find the determinant of ![\left[\begin{array}{ccc}1&2\\-3&-2\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%5C%5C-3%26-2%5Cend%7Barray%7D%5Cright%5D)
![\triangle_x = \left[\begin{array}{ccc}1&2\\5&-2\end{array}\right]\\\triangle_x = 1(-2)-2(5)\\\triangle_x = -2-10\\\triangle_x =-12](https://tex.z-dn.net/?f=%5Ctriangle_x%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%262%5C%5C5%26-2%5Cend%7Barray%7D%5Cright%5D%5C%5C%5Ctriangle_x%20%3D%201%28-2%29-2%285%29%5C%5C%5Ctriangle_x%20%3D%20-2-10%5C%5C%5Ctriangle_x%20%3D-12)
![\triangle_y = \left[\begin{array}{ccc}1&1\\-3&5\end{array}\right]\\\triangle_y = 1(5)-1(-3)\\\triangle_y = 5 + 3\\\triangle_y =8](https://tex.z-dn.net/?f=%5Ctriangle_y%20%3D%20%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D1%261%5C%5C-3%265%5Cend%7Barray%7D%5Cright%5D%5C%5C%5Ctriangle_y%20%3D%201%285%29-1%28-3%29%5C%5C%5Ctriangle_y%20%3D%205%20%2B%203%5C%5C%5Ctriangle_y%20%3D8)
The solution to the system of equations x + 2y = 1 and -3x-2y = 5 is:
x = -3, y = 2
Learn more here: brainly.com/question/4428059
First you plug in the data to the formula. So it will be 2(1/3+1/2). You then want to add the fractions together but must first find the common denominator which will be 6. So it is 2(2/6+3/6). The fractions then add up to be 5/6. So all you have to do is multiply it by 2 to get 5/3 which simplifies to 1 2/3 so it is D.
