Answer:
30 = 2x + 3y
Step-by-step explanation:
x is the number of pens bought and y is the number of notbooks bought you graph this and you get a graph that shows you all the combinations.
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:
63.66
Step-by-step explanation:
Mean=(65.9+80.8+60.8+46.5+64.3)/5
Mean=63.66
Answer:
62°
Step-by-step explanation:
180-118=62
62+62=124
180-124=56
118-56=62