Answer:
-2x-2y-2z I think that is answer
Answer:
The 99% confidence interval would be given by (0.286;0.562)
Step-by-step explanation:
Information given:
represent the families owned at least one DVD player
represent the total number of families
represent the estimated proportion of families owned at least one DVD player
In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by 
and 
. And the critical value would be given by:
The confidence interval for the mean is given by the following formula:
If we replace the values obtained we got:
The 99% confidence interval would be given by (0.286;0.562)
Answer:
A. The lowercase symbol, p, represents the probability of getting a test statistic at least as extreme as the one representing sample data and is needed to test the claim.
Step-by-step explanation:
The conditions required for testing of a claim about a population proportion using a formal method of hypothesis testing are:
1) The sample observations are a simple random sample.
2) The conditions for a binomial distribution are satisfied
3) The conditions np5 and nq5 are both satisfied. i.e n: p≥ 5and q≥ 5
These conditions are given in th options b,c and d.
Option A is not a condition for testing of a claim about a population proportion using a formal method of hypothesis testing.
You need to understand that you're solving for the average, which you already know: 90. Since you know the values of the first three exams, and you know what your final value needs to be, just set up the problem like you would any time you're averaging something.
Solving for the average is simple:
Add up all of the exam scores and divide that number by the number of exams you took.
(87 + 88 + 92) / 3 = your average if you didn't count that fourth exam.
Since you know you have that fourth exam, just substitute it into the total value as an unknown, X:
(87 + 88 + 92 + X) / 4 = 90
Now you need to solve for X, the unknown:
87
+
88
+
92
+
X
4
(4) = 90 (4)
Multiplying for four on each side cancels out the fraction.
So now you have:
87 + 88 + 92 + X = 360
This can be simplified as:
267 + X = 360
Negating the 267 on each side will isolate the X value, and give you your final answer:
X = 93
Now that you have an answer, ask yourself, "does it make sense?"
I say that it does, because there were two tests that were below average, and one that was just slightly above average. So, it makes sense that you'd want to have a higher-ish test score on the fourth exam.
We need to solve for x, we need to get x alone
Lets start by removing -5
Add 5 on both sides
Now to isolate x , we need to remove the square from x
To remove square , take square root on both sides
square and square root will get cancelled
So 
and 
