# 9.8 Exercises  (Page 2/5)

 Page 2 / 5

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.

• 2
• 0.1
• 0.12
• 16
• 15
• the weight of 1 small bag of candies
• the mean weight of 16 small bags of candies
• $N$ $\left(2,\frac{0\text{.}1}{\sqrt{\text{16}}}\right)$
• CI: (1.96, 2.04)
• EB = 0.04
• CI: (1.94, 2.06)
• EB = 0.06

where we get a research paper on Nano chemistry....?
nanopartical of organic/inorganic / physical chemistry , pdf / thesis / review
Ali
what are the products of Nano chemistry?
There are lots of products of nano chemistry... Like nano coatings.....carbon fiber.. And lots of others..
learn
Even nanotechnology is pretty much all about chemistry... Its the chemistry on quantum or atomic level
learn
da
no nanotechnology is also a part of physics and maths it requires angle formulas and some pressure regarding concepts
Bhagvanji
hey
Giriraj
Preparation and Applications of Nanomaterial for Drug Delivery
revolt
da
Application of nanotechnology in medicine
what is variations in raman spectra for nanomaterials
ya I also want to know the raman spectra
Bhagvanji
I only see partial conversation and what's the question here!
what about nanotechnology for water purification
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
Damian
yes that's correct
Professor
I think
Professor
Nasa has use it in the 60's, copper as water purification in the moon travel.
Alexandre
nanocopper obvius
Alexandre
what is the stm
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
Rafiq
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
Damian
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
LITNING
scanning tunneling microscope
Sahil
how nano science is used for hydrophobicity
Santosh
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
Rafiq
what is differents between GO and RGO?
Mahi
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
Rafiq
if virus is killing to make ARTIFICIAL DNA OF GRAPHENE FOR KILLED THE VIRUS .THIS IS OUR ASSUMPTION
Anam
analytical skills graphene is prepared to kill any type viruses .
Anam
Any one who tell me about Preparation and application of Nanomaterial for drug Delivery
Hafiz
what is Nano technology ?
write examples of Nano molecule?
Bob
The nanotechnology is as new science, to scale nanometric
brayan
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Damian
Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
how did you get the value of 2000N.What calculations are needed to arrive at it
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