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:
Step-by-step explanation:
Diameter = 28 cm
therefore, radius = 28 / 2 = 14 cm
Circumference = 2 π r
= 2 × 22 / 7 × 14
= <u><em>88 cm</em></u>
Hope this helps
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Answer:
The one you have selected is the right answer 126 times pi
Step-by-step explanation:
Exact answer - 395.840674
Answer:
undefined
Step-by-step explanation:
Sin(x) = 0 where x = 0
Cos(x) = 1 where x = 0
Cot(0) is undefined