Question
In: Statistics and Probability
A random sample of 84 items is taken, producing a sample mean of 43. The population...
A random sample of 84 items is taken, producing a sample mean of
43. The population standard deviation is 5.89. Construct a 90%
confidence interval to estimate the population mean.
Solutions
Expert Solution
( , )
Solution :
Given that,
Point estimate = sample mean = 
= 43
Population standard deviation = 
= 5.89
Sample size = n =84
At 90% confidence level the z is
= 1 - 90% = 1 - 0.90 = 0.1
/ 2 = 0.1 / 2 = 0.05
Z/2
= Z0.05 = 1.645 ( Using z table )
Margin of error = E = Z/2
* ( 
/
= 1.645 * ( 5.89 /
= 1.057
At 90% confidence interval estimate of the population mean
is,
- E < 
<
+ E
43 - 1.057 <
< 43 + 1.057
41.943 <
< 44.057
orchestra answered 2 years agoRelated Solutions
A simple random sample of 60 items resulted in a sample mean of 84. The population...
A simple random sample of 60 items resulted in a sample mean of
84. The population standard deviation is 15.
a. Compute the 95% confidence interval for the population mean
(to 1 decimal).
( , )
b. Assume that the same sample mean was obtained from a sample
of 120 items. Provide a 95% confidence interval for the population
mean (to 2 decimals).
( , )
How do you find the answers? Please write legibly! Thank
you!
From a normal population, a sample of 39 items is taken. The sample mean is 12...
From a normal population, a sample of 39 items is taken. The
sample mean is 12 and the sample standard deviation is 2. Construct
a 99% confidence interval for the population mean.
If a random sample of 100 items is taken from a population in which the proportion...
If a random sample of 100 items is taken from a population in
which the proportion of items having a desired attribute is p=0.45,
what is the probability that the proportion of successes in the
sample will be less than or equal to 0.49
The probability will be ____
If a random sample of 125 items is taken from a population in which the proportion...
If a random sample of 125 items is taken from a population in
which the proportion of items having a desired attribute is p =
0.16, what is the probability that the proportion of successes in
the sample will be more than 0.2?
13.If a random sample of 125 items is taken from a population in which the proportion...
13.If a random sample of 125 items is taken from a population in
which the proportion of items having a desired attribute is p =
0.16, what is the probability that the proportion of successes in
the sample will be more than 0.2?
A simple random sample of 70 items resulted in a sample mean of 60. The population...
A simple random sample of 70 items resulted in a sample mean of
60. The population standard deviation is σ = 15.
(a) Compute the 95% confidence interval for the population mean.
(Round your answers to two decimal places.)
_________ to _________
(b) Assume that the same sample mean was obtained from a sample
of 140 items. Provide a 95% confidence interval for the population
mean. (Round your answers to two decimal places.)
_________ to _________
(c) What is the...
A simple random sample of 30 items resulted in a sample mean of25. The population...
A simple random sample of 30 items resulted in a sample mean of
25. The population standard deviation is 7 . Round your answers to
two decimal places
a. What is the standard error of the mean,
?
b. At 95% confidence, what is the margin of
error?
A simple random sample of 30 items resulted in a sample mean of 30. The population...
A simple random sample of 30 items resulted in a sample mean of
30. The population standard deviation is 15.
a. Compute the 95% confidence interval for the
population mean. Round your answers to one decimal place.
( , )
b. Assume that the same sample mean was
obtained from a sample of 120 items. Provide a 95% confidence
interval for the population mean. Round your answers to two decimal
places.
( , )
A simple random sample of 60 items resulted in a sample mean of 80. The population...
A simple random sample of 60 items resulted in a sample mean of
80. The population standard deviation is
σ = 5.
(a)
Compute the 95% confidence interval for the population mean.
(Round your answers to two decimal places.)
to
(b)
Assume that the same sample mean was obtained from a sample of
120 items. Provide a 95% confidence interval for the population
mean. (Round your answers to two decimal places.)
to
A simple random sample of 60 items resulted in a sample mean of 80. The population...
A simple random sample of 60 items resulted in a sample mean of
80. The population standard deviation is
σ = 5.
(a)
Compute the 95% confidence interval for the population mean.
(Round your answers to two decimal places.)
to
(b)
Assume that the same sample mean was obtained from a sample of
120 items. Provide a 95% confidence interval for the population
mean. (Round your answers to two decimal places.)
to
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- Parallel Arrays This question is in MindTap Cengage Summary In this lab, you use what you...
- 5. You have invested 30 percent of your portfolio in Jacob, Inc., 40 percent is Bella...
- JAVA Write a test program that prompts the user to enter a series of integers and...
- (2) Cite an example on how organizations like Google, Facebook, Youtube etc collect data for image...
- The legal landscape is perpetually changing. Psychologists must remain abreast of these changes to avoid potentially...
- We are evaluating a project that costs $1.68 million, has a six-year life, and has no...
- In C++ Having call-by-reference allows one to use storeback parameters, i.e., parameters whose values are transmitted...
ADVERTISEMENT