Question
The mean and standard deviation of a random sample of n measurements are equal to 34.1...
The mean and standard deviation of a random sample of n measurements are equal to 34.1 and 3.6, respectively.
a. Find a 90% confidence interval for μ if n=144.
b. Find a 90% confidence interval for μ if n=576.
c. Find the widths of the confidence intervals found in parts a and b. What is the effect on the width of a confidence interval of quadrupling the sample size while holding the confidence coefficient fixed?
Homework Answers
Answer #1
Part a)
Confidence Interval
Lower Limit = 
Lower Limit = 33.6033
Upper Limit = 
Upper Limit = 34.5967
90% Confidence interval is ( 33.6033 , 34.5967 )
Width of CI = 34.5967 - 33.6033 = 0.9933
Confidence Interval
Lower Limit = 
Lower Limit = 33.8529
Upper Limit = 
Upper Limit = 34.3471
90% Confidence interval is ( 33.8529 , 34.3471 )
Width of CI = 34.3471 - 33.8529 = 0.4943
Part c)
As sample size increase, width of confidence interval become narrow.
Not the answer you're looking for?
Similar Questions
The mean and standard deviation of a random sample of n measurements are equal to 33.9...
The mean and standard deviation of a random sample of n
measurements are equal to 33.9 and 3.3, respectively.
a. Find the lower limit, the upper limit and the margin of error
for a 95% confidence interval for m if n = 100.
b. Find the lower limit, the upper limit and the margin of error
for a 95% confidence interval for m if n = 400.
A simple random sample of size n is drawn from a population that is normally distributed....
A simple random sample of size n is drawn from a population that
is normally distributed. The sample mean, x, is found to be 113,
and the sample standard deviation, s, is found to be 10.
(a) Construct a 90% confidence interval about μ if the sample
size, n, is 22.
(b) Construct a 90% confidence interval about μ if the sample
size, n, is 15.
(c) Construct an 80% confidence interval about μ if the
sample size, n, is...
a simple random sample of size n is drawn. the sample mean, x̄, is found to...
a simple random sample of size n is drawn. the sample
mean, x̄, is found to be 29.5 and the sample standard deviation, s,
is found to be 8.4
a) construct a 90% confidence interval for μ if the
sample size, n, is 40
b) construct a 90% confidence interval for μ if the
sample size n is 100
c) how does increasing the sample size affect the
margin of error, E
You are given the sample mean and the population standard deviation. Use this information to construct...
You are given the sample mean and the population standard
deviation. Use this information to construct the 90% and 95%
confidence intervals for the population mean. Interpret the results
and compare the widths of the confidence intervals. If convenient,
use technology to construct the confidence intervals.
A random sample of 60 home theater systems has a mean price of
$147.00. Assume the population standard deviation is $19.40.
Construct a 90% confidence interval for the population mean.
The 90% confidence interval...
A simple random sample of size n is drawn from a population that is normally distributed....
A simple random sample of size n is drawn from a population that
is normally distributed. The sample mean, overbar x, is found to
be 115, and the sample standard deviation, s, is found to be 10.
(a) Construct a 98% confidence interval about μ if the sample
size, n, is 20. (b) Construct a 98% confidence interval about μ
if the sample size, n, is 25. (c) Construct a 99% confidence
interval about μ if the sample size, n,...
A simple random sample of size n is drawn from a population that is normally distributed....
A simple random sample of size n is drawn from a population that
is normally distributed. The sample mean, is found to be 109, and
the sample standard deviation, s, is found to be
10.
(a) Construct a 98% confidence interval about m μ if the
sample size, n, is 21.
(b) Construct a 98% confidence interval about mu μ if the
sample size, n, is 26.
(c) Construct a 99% confidence interval about mu μ if the
sample size,...
A simple random sample of size n is drawn. The sample mean is found to be...
A simple random sample of size n is drawn. The sample mean is
found to be 35.1, and the sample standard deviation is found to be
8.7.
a. Construct the 90% confidence interval if the sample size is
40.
b. Construct the 98% confidence interval if the sample size is
40.
c.How does increasing the level of confidence affect the size of
the margin of error?
d. Would you be able to compute the confidence intervals if the
sample size...
A simple random sample of size n is drawn from a population that is normally distributed....
A simple random sample of size n is drawn from a population that
is normally distributed. The sample mean,
x,
is found to be
115,
and the sample standard deviation, s, is found to be
10.
(a) Construct
a
95%
confidence interval about
μ
if the sample size, n, is
22.
(b) Construct
a
95%
confidence interval about
μ
if the sample size, n, is
12.
(c) Construct
a
90%
confidence interval about
μ
if the sample size, n, is...
A simple random sample of size n is drawn from a population that is normally distributed....
A simple random sample of size n is drawn from a population that
is normally distributed. The sample mean, x overbar, is found to
be 108, and the sample standard deviation, s, is found to be
10.
1. A) Construct a 96% confidence interval about μ if
the sample size, n, is 24.
1. B) Construct a 96% confidence interval about μ if
the sample size, n, is 20.
How does increasing the sample size affect the margin
of error,...
Mean Sample standard deviation Population standard deviation Sample size Confidence level Confidence interval 100 20 na...
Mean
Sample standard deviation
Population standard deviation
Sample size
Confidence level
Confidence interval
100
20
na
25
95 %
100
20
na
25
90 %
100
40
na
25
90 %
100
40
n.a.
16
90 %
100
n.a.
40
16
90 %
How does the confidence level affect the width of the confidence
interval, other things equal?
How does the size of the standard deviation affect the width of
the confidence interval, other things equal?
How does sample size...
ADVERTISEMENT
Need Online Homework Help?
Get Answers For Free
Most questions answered within 1 hours.
ADVERTISEMENT
Active Questions
asked 3 minutes ago
asked 12 minutes ago
asked 24 minutes ago
asked 26 minutes ago
asked 27 minutes ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago