Answer:
A. 30.144
Step-by-step explanation:
This is a Chi-Squared test
Given:
- [tex]n=20[/tex]
- [tex]s=18[/tex]
- [tex]\textsf{H}_0:\sigma^2=384[/tex]
- [tex]\textsf{H}_1:\sigma^2 > 384[/tex]
- The significance level is 5%, so [tex]\alpha= 0.05[/tex]
To use the Chi-Square distribution table, you need to know two values:
- Degrees of freedom = (n - 1)
- Significance level
Degrees of Freedom = n - 1 = 20 - 1 = 19
The significance level is 5%, so [tex]\alpha= 0.05[/tex]
This is a one-tailed test since [tex]\textsf{H}_1:\sigma^2 > 384[/tex] so Upper tail area = 0.05
Reading from the table (attached), the critical value is: 30.144
(This means that we reject [tex]\textsf{H}_0[/tex] if the test statistic is greater than 30.144)
