Answer:
A
Step-by-step explanation:
I hope i helped
Answer:
Step-by-step explanation:
Since the population standard deviation 
is unknown, and the sample standard deviation 
, must replace it, the 
distribution must be used for the confidence interval.
The sample size is n=8.
The degree of freedom is 
, 
.
With 95% confidence level, the 
(significance level) is 5%.
Hence with 7 degrees of freedom, 
. (Read from the t-distribution table see attachment)
The 95% confidence interval can be found by using the formula:
.
The sample mean is 
hours.
The sample sample standard deviation is 
hours.
We now substitute all these values into the formula to obtain:
.
We are 95% confident that the population mean is between 26.12 and 31.48 hours.
Answer:
because the shape includes a curve
Answer:
sqrt5/5
Step-by-step explanation:
Answer:
Negative correlation.
Step-by-step explanation:
Negative correlation means that as x increases, y decreases
Positive correlation means that as x increases, y also increases.
No correlation means that neither of the two above cases happens.
In the graph, we can see that on the right (when x is negative) the general y values are larger.
As x increases, the y-values decrease.
(Particularly, we could adjust these data with a linear equation with a negative slope)
Then this is a negative correlation.
