Let the test statistic T have a t distribution when H0 is true. Give the significance level for each of the following situation.
A. Ha: mu > m0, df = 15, rejection region t > 3.733
B. Ha : mu < mu 0, n = 24, rejection region t < - 2.500
C. Ha: mu not = mu 0, n = 31, rejection region t >1.697 or t < - 1.697

Respuesta :

Answer:

a) The degrees of freedom are given by:

[tex]df = 15[/tex]

And the rejection region is [tex]t_{\alpha}<3.733[/tex]

And the significance level would be:

[tex]P(t_{15} >3.733) =0.001[/tex]

b) The degrees of freedom are given by:

[tex]df = 24-1=23[/tex]

And the rejection region is [tex]t_{\alpha} <-2.5[/tex]

And the significance level would be:

[tex]P(t_{23} <-2.5) =0.0099 \approx 0.01[/tex]

c) The degrees of freedom are given by:

[tex]df = 31-1=30[/tex]

And the rejection region is [tex]t_{\alpha} <-1.697[/tex] or [tex]t_{\alpha} >1.697[/tex]

And the significance level would be:

[tex]2*P(t_{30} <-1.697) =0.10[/tex]

Step-by-step explanation:

Part a

We have the following system of hypothesis:

Null hypothesis: [tex]\mu \leq \mu_0 [/tex]

Alternative hypothesis: [tex]\mu > \mu_0 [/tex]

The degrees of freedom are given by:

[tex]df = 15[/tex]

And the rejection region is [tex]t_{\alpha}<3.733[/tex]

And the significance level would be:

[tex]P(t_{15} >3.733) =0.001[/tex]

Part b

We have the following system of hypothesis:

Null hypothesis: [tex]\mu \geq \mu_0 [/tex]

Alternative hypothesis: [tex]\mu < \mu_0 [/tex]

The degrees of freedom are given by:

[tex]df = 24-1=23[/tex]

And the rejection region is [tex]t_{\alpha} <-2.5[/tex]

And the significance level would be:

[tex]P(t_{23} <-2.5) =0.0099 \approx 0.01[/tex]

Part c

We have the following system of hypothesis:

Null hypothesis: [tex]\mu = \mu_0 [/tex]

Alternative hypothesis: [tex]\mu \neq \mu_o[/tex]

The degrees of freedom are given by:

[tex]df = 31-1=30[/tex]

And the rejection region is [tex]t_{\alpha} <-1.697[/tex] or [tex]t_{\alpha} >1.697[/tex]

And the significance level would be:

[tex]2*P(t_{30} <-1.697) =0.10[/tex]