Answer: 2.093
Step-by-step explanation:
As per give , we have
Sample size : n= 20
Degree of freedom : df= n-1=19
Significance level : 
Since , the sample size is small (n<30) so we use t-test.
For confidence interval , we find two-tailed test value.
Using students's t-critical value table,
Critical t-value : 
Thus, the critical value for the 95% confidence interval = 2.093
The questions is, when z=9, 3z = ? When you multiply 3*9, you get 27
Answer:
c=45
Step-by-step explanation:
36^2+27^2=c2
1296+729=c2
2095=c2
Then square root it to get
c=45
we have
----> inequality 1
The solution of the inequality 1 is the shaded area below the solid red line
The solution is the region D and region C
-----> inequality 2
The solution of the inequality 2 is the shaded area above the solid blue line
The solution is the region B and region C
The solution of the system is the common area
so
The solution is the region C
see the attached figure
therefore
the answer is the option C
Region C