I need someone who is excellent in stats. and knows their stuff. I need a perfect score on these 4 questions. question 64,20,32,38

( )
( )
38)
Given that
Number of people randomly selected from their mailing list 1000
Number of people the company contacts who may
they buy something 123
Proportion of people the company contacts who may
the
n
x
=
=
( )
( ) ( )
( )
( )
0.950.101 1
2 2
1
2
y buy something
123
1000
0.123
Using Excel function to find critical value for 90% confidence interval
1 0.90 0.10
Z
Using Excel function
Z
=NORMSINV 0.95
1.645
x
p
n
Z Z



− −
−
=
=
=
= − =
= =
=
=
( )
( )
( )
^ ^
^
)
90% confidence interval for precentage of people the
company contacts who may buy something
1
0.123 1 0.123
0.123 1.645
1000
0.123 1 0.123
0.123 1.645
1000
Critical
a
p
p p
p Z
n
  
−  
  = 
 
 
 
 −
 = 
 
 
 −
= 


( )
0.107871
0.010386
0.0171
Lower value = 0.0171 0.1059
Convert the percentage value = 0.1059*100 = 10.59%
Upper value = 0.0171 0.1401
Convert the percen
0.123 1.645
1000
0.123 1.645
0.123
0.123
0.123

=



 
=   
 
= 
= 

=+

tage value = 0.1401*100 = 14.01%
− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

)
90% confidence for the Percentage of people the company
contact who may buy something is lies between 10.59%
and 14.01%
)
90% confidence interval:
it mean that 90% of
b
c
− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −
( )
all possible samples have a 90%
confidence that contain population proportion .
)
The mailing cost is effective From the part (a) {90% confidence
for the Percentage of pe
p
d
− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −
ople the company contact who may buy
something is lies between 10.59% and 14.01%} contains only
returns higher than 5%
− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −
( )
( )
^
32)
Given that
Numeber of red snapper packeges are tested 22
Numeber of red snapper packeges are mislabeled 12
Proportion of red snapper packeges are mislabeled
12
22
0.545
)
It's not clear how
n
x
x
p
n
a
=
=
 
= 
 
=
=
the sample was chosen, but we will assime
that the seafood packages, which came from varous kinds of
establishments in 3stages is representative of all seafood
packages.22 is far less than 10% of all
( )
^
^
^
packages of red
snappers.
n 22 0.545 12
1 22 1 0.545 10
Both of these are atleast 10 np 10 and 1 10
So this sample is large.
p
and
n p
n p
=  =
 
− =  − = 
 
  
 −   
  
− − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − − −

( ) ( )
( )
( )
0.9750.051 1
2 2
1
2
)
Using Excel function to find critical value for 95%
confidence interval
1 0.95 0.05
Z
Using Excel function
Z
=NORMSINV 0.975
1.96
90% confidence interval for propotion of "red sn
b
Z Z



− −
−
= − =
=...