Question
A random sample of 20 observations is used to estimate the population mean. The sample mean...
A random sample of 20 observations is used to estimate the population mean. The sample mean and the sample standard deviation are calculated as 152 and 74, respectively. Assume that the population is normally distributed.
- What is the margin of error for a 95% confidence interval for the population mean?
- Construct the 95% confidence interval for the population mean.
- Construct the 90% confidence interval for the population mean.
- Construct the 78% confidence interval for the population mean. Hint: Use Excel function =t.inv.2t to find the value of t for the interval calculation.
Homework Answers
Answer #1
Not the answer you're looking for?
Similar Questions
A random sample of 24 observations is used to estimate the population mean. The sample mean...
A random sample of 24 observations is used to estimate the
population mean. The sample mean and the sample standard deviation
are calculated as 104.6 and 28.8,
respectively. Assume that the population is normally
distributed. Construct the 90% confidence interval for the
population mean. Then, construct the 95% confidence
interval for the population mean. Finally, use your answers to
discuss the impact of the confidence level on the width of the
interval.
A random sample of 34 observations is used to estimate the population variance. The sample mean...
A random sample of 34 observations is used to estimate the
population variance. The sample mean and sample standard deviation
are calculated as 51.5 and 5.6, respectively. Assume that the
population is normally distributed. (You may find it useful
to reference the appropriate table: chi-square table or F
table)
a. Construct the 90% interval estimate for the
population variance.
b. Construct the 95% interval estimate for the
population variance
A random sample of 14 observations is used to estimate the population mean. The sample mean...
A random sample of 14 observations is used to estimate the
population mean. The sample mean and the sample standard deviation
are calculated as 158.4 and 30.10, respectively. Assume that the
population is normally distributed. [You may find it useful
to reference the t table.]
a. Construct the 90% confidence interval for the
population mean. (Round intermediate calculations to at
least 4 decimal places. Round "t" value to 3 decimal
places and final answers to 2 decimal places.)
b. Construct...
11. A random sample of 22 observations is used to estimate the population mean. The sample...
11. A random sample of 22 observations is used to estimate the
population mean. The sample mean and the sample standard deviation
are calculated as 135.5 and 30.50, respectively. Assume that the
population is normally distributed. [You may find it useful
to reference the t table.]
a. Construct the 90% confidence interval for the
population mean.
(Round intermediate calculations to at least 4 decimal
places. Round "t" value to 3 decimal places and final
answers to 2 decimal places.)
Confidence...
Suppose a random sample of size 11 was taken from a normally distributed population, and the...
Suppose a random sample of size 11 was taken from a normally
distributed population, and the sample standard deviation was
calculated to be s = 6.5. We'll assume the sample mean is 10 for
convenience. a) Calculate the margin of error for a 90% confidence
interval for the population mean. Round your response to at least 3
decimal places. Number b) Calculate the margin of error for a 95%
confidence interval for the population mean. Round your response to
at...
The sample size required to estimate, at 95% confidence, a population mean with a maximum allowable...
The sample size required to estimate, at 95% confidence, a
population mean with a maximum allowable margin of error of +/- 1.5
when the population standard deviation is 5 is ____
observations.
The sample size required to estimate, at 90% confidence, a
population proportion with a maximum allowable margin of error of
+/- 3.00 percentage points is ____ observations.
(S 9.2) Recall that a confidence interval for the sample mean can be calculated using the...
(S 9.2) Recall that a confidence interval for the sample mean
can be calculated using the interval
x¯?tn?1?sn??????x¯+tn?1?sn???
Thus, the margin of error is
tn?1?sn???
We can recover the margin of error from an interval constructed
on the calculator using algebra.
Suppose a random sample of size 16 was taken from a normally
distributed population, and the sample standard deviation was
calculated to be s = 6.3. We'll assume the sample mean is
10 for convenience.
a) Calculate the margin...
A simple random sample of 11 observations is derived from a normally distributed population with a...
A simple random sample of 11 observations is derived from a
normally distributed population with a known standard deviation of
2.2. [You may find it useful to reference the z
table.]
a. Is the condition that X−X− is normally distributed
satisfied?
Yes
No
b. Compute the margin of error with 95%
confidence. (Round intermediate calculations to at least 4
decimal places. Round "z" value to 3 decimal places and
final answer to 2 decimal places.)
c. Compute the margin of...
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 10 observations is derived from a normally distributed population with a...
A simple random sample of 10 observations is derived from a
normally distributed population with a known standard deviation of
2.1. [Use Excel instead of the z
table.]
a. Is the condition that X−X− is normally distributed
satisfied?
_Yes
_No
b. Compute the margin of error with 99%
confidence. (Round intermediate calculations to at least 4
decimal places. Round "z" value to 3 decimal places and
final answer to 2 decimal places.)
c. Compute the margin of error with 95%...
ADVERTISEMENT
Need Online Homework Help?
Get Answers For Free
Most questions answered within 1 hours.
ADVERTISEMENT
Active Questions
asked 59 seconds ago
asked 7 minutes ago
asked 26 minutes ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 2 hours ago
asked 2 hours ago
asked 2 hours ago
asked 2 hours ago