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