Respuesta :
Answer:
The critical value is T = 2.7787
Step-by-step explanation:
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 27 - 1 = 26
99% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 26 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.99}{2} = 0.995[/tex]. So we have T = 2.7787
The critical value is T = 2.7787
The critical values define the values to cut-off in a region where the test statistic does not belong
The critical value is [tex]\mathbf{-2.778715}[/tex]
The given parameters are:
[tex]\mathbf{n = 27}[/tex]
[tex]\mathbf{CL = 99\%}[/tex]
First, we calculate the significance level
[tex]\mathbf{\alpha = \frac{1 - CL}{2}}[/tex]
Substitute 99% for CL
[tex]\mathbf{\alpha = \frac{1 - 99\%}{2}}[/tex]
Express percentage as decimal
[tex]\mathbf{\alpha = 1 - \frac{1 - 0.99}{2}}[/tex]
[tex]\mathbf{\alpha =1 - \frac{0.01}{2}}[/tex]
[tex]\mathbf{\alpha = 1 - 0.005}[/tex]
[tex]\mathbf{\alpha = 0.995}[/tex]
Next, calculate the degrees of freedom
[tex]\mathbf{df = n -1}[/tex]
Substitute 27 for n
[tex]\mathbf{df = 27 -1}[/tex]
[tex]\mathbf{df = 26}[/tex]
At [tex]\mathbf{df = 26}[/tex] and [tex]\mathbf{\alpha = 0.995}[/tex], the critical value is -2.778715
So, we have:
[tex]\mathbf{t_c = -2.778715}[/tex]
Hence, the critical value is [tex]\mathbf{-2.778715}[/tex]
Read more about critical values at:
https://brainly.com/question/2395306