In: Statistics and Probability
In a survey of 2085 adults in a certain country conducted during
a period of economic uncertainty, 67% thought that wages paid to
workers in industry were too low.
The margin of error was 9 percentage points with 90%
confidence.
For parts (a) through (d) below, which represent a reasonable
interpretation of the survey results?
For those that are not reasonable, explain the flaw.
(a) We are 90% confident 67% of adults in the country during
the period of economic uncertainty
felt wages paid to workers in industry were too low.
Is the interpretation reasonable?
A.
The interpretation is reasonable.
B.
The interpretation is flawed. The interpretation indicates that the
level of confidence is varying.
C.
The interpretation is flawed. The interpretation provides no
interval about the population proportion.
D.
The interpretation is flawed. The interpretation suggests that this
interval sets the standard for all the other intervals, which is
not true.
(b) We are 81% to 99% confident 67% of adults in the country
during the period of economic uncertainty felt wages paid to
workers in industry were too low.
Is the interpretation reasonable?
A.
The interpretation is reasonable.
B.
The interpretation is flawed. The interpretation provides no
interval about the population proportion.
C.
The interpretation is flawed. The interpretation suggests that this
interval sets the standard for all the other intervals, which is
not true.
D.
The interpretation is flawed. The interpretation indicates that the
level of confidence is varying.
(c) We are 90% confident that the interval from 0.58 to 0.76
contains the true proportion of adults in the country during the
period of economic uncertainty who believed wages paid to workers
in industry were too low.
Is the interpretation reasonable?
A.
The interpretation is reasonable.
B.
The interpretation is flawed. The interpretation provides no
interval about the population proportion.
C.
The interpretation is flawed. The interpretation indicates that the
level of confidence is varying.
D.
The interpretation is flawed. The interpretation suggests that this
interval sets the standard for all the other intervals, which is
not true.
(d) In 90% of samples of adults in the country during the
period of economic uncertainty, the proportion who believed wages
paid to workers in industry were too low is between 0.58 and
0.76.
Is the interpretation reasonable?
A.
The interpretation is reasonable.
B.
The interpretation is flawed. The interpretation provides no
interval about the population proportion.
C.
The interpretation is flawed. The interpretation indicates that the
level of confidence is varying.
D.
The interpretation is flawed. The interpretation suggests that this
interval sets the standard for all the other intervals, which is
not true.
In a survey of 2085 adults in a certain country conducted during
a period of economic uncertainty, 67% thought that wages paid to
workers in the industry were too low.
The margin of error was 9 percentage points with 90%
confidence.
( p +- E) = ( 0.67 +- 0.09) = (0.67 -0.09 ; 0.67 +0.09 ) = ( 0.58 , 0.76)
The 90% confidence interval is (0.58 , 0.76)
(a) We are 90% confident 67% of adults in the country during
the period of economic uncertainty
felt wages paid to workers in the industry were too low.
Here we are not defining any confidence interval. we only gave a point estimate.
Answer:- The interpretation is flawed. The interpretation provides no interval about the population proportion.
b)
We are 81% to 99% confident 67% of adults in the country
during the period of economic uncertainty felt wages paid to
workers in the industry were too low.
Is the interpretation reasonable?
No here confidence interval is varying which is not true.
Answer:- D.The interpretation is flawed. The interpretation indicates that the level of confidence is varying.
c)
We are 90% confident that the interval from 0.58 to 0.76
contains the true proportion of adults in the country during the
period of economic uncertainty who believed wages paid to workers
in the industry were too low.
Is the interpretation reasonable?
yes, it is reasonable interpretation.
Answer:- A.The interpretation is
reasonable.
d) In 90% of samples of adults in the country during the period of economic uncertainty, the proportion who believed wages paid to workers in the industry were too low is between 0.58 and 0.76.
Here it is stated that the sample adults.which is not reasonable.
Answer:- D.The interpretation is flawed. The interpretation suggests that this interval sets the standard for all the other intervals, which is not true.