Suppose that a committee is studying whether or not there is waste of time in our judicial system. It is interested in the mean amount of time individuals waste at the courthouse waiting to be called for service. The committee randomly surveyed 81 people. The sample mean was 8 hours with a sample standard deviation of 4 hours.
$\overline{x}=$$\text{\_\_\_\_\_\_\_\_}$
${s}_{x}=$$\text{\_\_\_\_\_\_\_\_}$
$n=$$\text{\_\_\_\_\_\_\_\_}$
$n-1=$$\text{\_\_\_\_\_\_\_\_}$
Define the Random Variables
$X$ and
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 95% confidence interval for the population mean time wasted.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
Explain in a complete sentence what the confidence interval means.
8
4
81
80
${t}_{\text{80}}$
CI: (7.12, 8.88)
EB = 0.88
Suppose that an accounting firm does a study to determine the time needed to complete one person’s tax forms. It randomly surveys 100 people. The sample mean is 23.6 hours. There is a known standard deviation of 7.0 hours. The population distribution is assumed to be normal.
$\overline{x}=$$\text{\_\_\_\_\_\_\_\_}$
$\sigma =$$\text{\_\_\_\_\_\_\_\_}$
${s}_{x}=$$\text{\_\_\_\_\_\_\_\_}$
$n=$$\text{\_\_\_\_\_\_\_\_}$
$n-1=$$\text{\_\_\_\_\_\_\_\_}$
Define the Random Variables
$X$ and
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 90% confidence interval for the population mean time to complete the tax forms.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
If the firm wished to increase its level of confidence and keep the error bound the same by taking another survey, what changes should it make?
If the firm did another survey, kept the error bound the same, and only surveyed 49 people, what would happen to the level of confidence? Why?
Suppose that the firm decided that it needed to be at least 96% confident of the population mean length of time to within 1 hour. How would the number of people the firm surveys change? Why?
A sample of 16 small bags of the same brand of candies was selected. Assume that the population distribution of bag weights is normal. The weight of each bag was then recorded. The mean weight was 2 ounces with a standard deviation of 0.12 ounces. The population standard deviation is known to be 0.1 ounce.
$\overline{x}=$$\text{\_\_\_\_\_\_\_\_}$
$\sigma =$$\text{\_\_\_\_\_\_\_\_}$
${s}_{x}=$$\text{\_\_\_\_\_\_\_\_}$
$n=$$\text{\_\_\_\_\_\_\_\_}$
$n-1=$$\text{\_\_\_\_\_\_\_\_}$
Define the Random Variable
$X$ , in words.
Define the Random Variable
$\overline{X}$ , in words.
Which distribution should you use for this problem? Explain your choice.
Construct a 90% confidence interval for the population mean weight of the candies.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
Construct a 98% confidence interval for the population mean weight of the candies.
State the confidence interval.
Sketch the graph.
Calculate the error bound.
In complete sentences, explain why the confidence interval in (f) is larger than the confidence interval in (e).
In complete sentences, give an interpretation of what the interval in (f) means.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
Source:
OpenStax, Collaborative statistics homework book: custom version modified by r. bloom. OpenStax CNX. Dec 23, 2009 Download for free at http://legacy.cnx.org/content/col10619/1.2
Google Play and the Google Play logo are trademarks of Google Inc.
Notification Switch
Would you like to follow the 'Collaborative statistics homework book: custom version modified by r. bloom' conversation and receive update notifications?