Answer:
The 80% confidence interval for the population mean is between 28.32 characters and 31.68 characters.
Step-by-step explanation:
We have the standard deviation for the population, so we can use the normal distribution. If we had the standard deviation for the sample, we would have to use the t-distribution.
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
In which 
is the standard deviation of the population and n is the size of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 30 - 1.68 = 28.32 characters.
The upper end of the interval is the sample mean added to M. So it is 30 + 1.68 = 31.68 characters.
The 80% confidence interval for the population mean is between 28.32 characters and 31.68 characters.
Answer:
B ( -1, -8)
Step-by-step explanation:
A ( -7, -6)
midpt (-4, -7)
Equation:
(x + 3, y - 1)
Solve for B:
(-4, -7)
(x + 3, y - 1)
( -1, -8)
The df value for the t statistic for this study is 12.
To calculate the df value or degree of freedom we have to learn about test-statistic.
<h3>What is t statistics and how is it related to df(degree of freedom)?</h3>
In the field of statistics , T-statistic is the ratio of the estimated value of the perimeter to its standard error. Degree of freedom or df value denotes the number of data (from a sample) is used to calculate the estimate .
Importantly the degree of freedom is different from the sample space of an experiment.
The formula for calculating the df of a function is given by
df=N1+N2-2
So in the given question, N1=6 and N2=8
Substituting the values we get df=N1+N2-2=8+6-2=12 .
Therefore the value of the degree of freedom is 12.
To learn more about t-statistic and df values:
brainly.com/question/15236063
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Answer:
f(4) = 22
Step-by-step explanation:
I think that you type wrongly.
we have f(1) = -5
and f(n) = f(n-1) + 9
Find f(4)
Then
with n= 2 we have f(2) = f(1) + 9 = - 5+ 9= 4
with n= 3 we have f(3) = f(2) + 9 = 4 + 9= 13
and finally with n= 4 we find f(4) = f(3) + 9 = 13+ 9= 22
So f(4) = 22
Hope you understand.
q + 20 = p
Since the number p is 20 more than the number q, you would put it in an equation to identify the relationship between these numbers. 20 plus q makes p.
