Answer:
d. Mail surveys to 1,000 subscribers randomly selected from those who have received the magazine for 5 years or more and 1,000 subscribers randomly selected from those who have received the magazine for 1 year or less.
Step-by-step explanation:
In the case of the publishers of the magazine, in order to avoid bias, they would adopt he approach mentioned in the above statement. That is, to consider both those that have recieved the magazine for the past five years or more as well as those who have recieve the magazine for the past one year or less.
<em>This would help them to have a balanced outcome in the survey because all, would attend the the survey with a free mindset rather than baised mindset.</em>
Answer: 30%
The probability of black is 60% and the probability of orange is 50%. The probability of getting both is then the product of their probabilities:
60% multiplied by 50%=0.6 times 0.5=0.3 of 30%
HOPE THIS HELPS!!!!!!!:)
Answer:
Step-by-step explanation:
A) From the order of the exercise we already know that the intersection points lies on the Y-axis, so its coordinates are P(0;y;0). In order to find it, we only need to substitute the equation 4x+4z=0 into the equation 4x+3y+4z=1. Then,
1=4x+3y+4z = 3y + (4x+4z)= 3y+0.
From the expression above it is easy to obtain that y=1/3, and the intersection point is P(0;1/3;0).
B) To obtain the parallel vector to both planes we use the cross product of the normal vector of the planes.
![\left[\begin{array}{ccc}i&j&k\\4&3&4\\4&0&4\end{array}\right] = 12i-0j+12k](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7Di%26j%26k%5C%5C4%263%264%5C%5C4%260%264%5Cend%7Barray%7D%5Cright%5D%20%3D%2012i-0j%2B12k)
As we want a unit vector, we must calculate the modulus of u:
.
Thus, the wanted vector is 
. Therefore,
.
C) In order to obtain the vector equation of the intersection line of both planes, we just need to put together the above results.
where 
is a real number.
