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 
So 5,10,15,20,25,30,35,40,45 so Aylson needs 1 more bead. Because 45 beads are already used!
Answer:
342.22$
Step-by-step explanation:
Across the largest side is going to be largest angle, and across the smallest side -smallest angle.
Sides:
BC = 9 < AB = 13 < CA = 17.
Angles that are across sides: A < C < B.
Answer is d- A C B.