We know:

We have

Substitute:


Only 4 and 10 meet the requirements of the question.
--------------------------------------------------------------------
40 and 1 NOT, because 40 > 12
20 and 2 NOT, because 20 > 12
5 and 8 NOT because GCF(5, 8) = 1
Answer:


The confidence interval of standard deviation is:
to 
Step-by-step explanation:
Given

See attachment for the formatted data
Solving (a): The mean
This is calculated as:

So, we have:




Solving (b): The standard deviation
This is calculated as:




--- approximated
Solving (c): 95% confidence interval of standard deviation
We have:

So:



Calculate the degree of freedom (df)



Determine the critical value at row
and columns
and 
So, we have:
---- at 
--- at 
So, the confidence interval of the standard deviation is:
to 
to 
to 
to 
Answer:
you talking to specific people or can anyone join
Step-by-step explanation:
Answer:
B, D
Step-by-step explanation:
Solve all equations:
A.

This is false equality, so this equation has no solutions.
B.

This equality is true for all values of x, so this equation has infinitely many solutions.
C.

This equation has the unique solution.
D.

This equality is true for all values of x, so this equation has infinitely many solutions.
E.

This equation has the unique solution.