Answer:
Step-by-step explanation:
The given system is:
Since I prefer to use smaller numbers I'm going to divide both sides of the first equation by 3 and both sides of the equation equation by 6.
This gives me the system:
We could solve the first equation for 
and replace the second with that.
Let's do that.
Subtract 
on both sides:
So we are replacing the second in the second equation with 
which gives us:
Now recall the first equation we arranged so that was the subject. I'm referring to .
We can now find given that using the equation .
Let's do that.
with :
So the solution is (8,-1).
We can check this point by plugging it into both equations.
If both equations render true for that point, then we have verify the solution.
Let's try it.
with 
:
is a true equation so the "solution" looks promising still.
with :
is also true so the solution has been verified since both equations render true for that point.
Answer:
Step-by-step explanation:
a) Sample statistics are used to estimate population value. Since 48% is a sample proportion, therefore, it is a sample statistic.
b) For 95% confidence level, z* = 1.96.
\hat{p}\pm z^* \sqrt{\frac{\hat{p}(1-\hat{p})}{n}}= 0.61\pm 0.61\sqrt{\frac{0.61(1-0.61)}{1578}}=0.61\pm 0.024 \ or (0.586, 0.634).
We are 95% confident that the true proportion of US residents who think marijuana should be made legal lies between 58.6% and 63.4%.
c)
\\np=1578(0.61)=962.58
\\n(1-p)=1578(1-0.61)=615.42
Since both np and n(1-p), are at least 10, the normal model is a good approximation for these data.
d) As the lower limit of confidence interval is less than 0.5, less than 50% population is also a plausible value of true proportion. This means the statement "Majority of Americans think marijuana should be legalized" is not justified.
Alice should pick the enlarged-photo with dimensions of 8-inch by 10-inch.
Step-by-step explanation:
Step 1:
In order for a part of the photo to not be cut off, the enlarged photo's dimensions should be of a constant ratio with the original photo's dimensions.
We divide the dimensions of the enlarged-photo with the dimensions of the original photo to check which has a constant ratio.
Step 2:
The original photo was a 4-inch by 5-inch photo.
Option 1 is 7-inch by 9-inch, so the ratios are
The ratios are different so this cannot be the enlarged photo's dimensions.
Option 2 is 8-inch by 10-inch, so the ratios are
The ratios are the same so this can be the enlarged photo's dimensions.
Option 3 is 12-inch by 16-inch, so the ratios are
The ratios are different so this cannot be the enlarged photo's dimensions.
So the enlarged-photo with dimensions of 8-inch by 10-inch should be picked.
Answer:
apart from using the hoc to predict the college students gpa, some other variables can be used
1. the students intelligent quotient
2. ability to remember
3. study time
4. gym practice
Step-by-step explanation:
<u>1. the students intelligent quotient</u>
<u>gpa</u><u> </u>has a positive relationship with iq. they are both directly related. The more the iq of a a student, the greater is his ability to understand and have a good gpa. the slope will therefore be positive and be in an upward direction.
2. <u>ability to remember</u>
the gpa of students who have a good ability to remember but do not have a good grasp of the subject may not be high. the slope would be in a slightly upward direction
3. <u>study time</u>
gpa and practice have a positive relationship. the more a student studies, the more likelihood exists of having a better gpa. the slope would be upward bound.
4. <u>gym</u><u> </u><u>practice</u>
gpa and gym practice are not related so the slope would be in a downward direction.
when interpreting the direction of relationship after carrying out such an analysis, it is useful to watch out for the accompanying signs of the variables. if the sign of the beta coefficient is positive then a positive relationship with the dependent variable exists.
Answer: 0.05
Step-by-step explanation:
Let M = Event of getting an A in Marketing class.
S = Event of getting an A in Spanish class,
i.e. P(M) = 0.80 , P(S) = 0.60 and P(M∩S)=0.45
Required probability = P(neither M nor S)
= P(M'∩S')
= P(M∪S)' [∵P(A'∩B')=P(A∪B)']
=1- P(M∪S) [∵P(A')=1-P(A)]
= 1- (P(M)+P(S)- P(M∩S)) [∵P(A∪B)=P(A)+P(B)-P(A∩B)]
= 1- (0.80+0.60-0.45)
= 1- 0.95
= 0.05
hence, the probability that Helen does not get an A in either class= 0.05
