# 9.8 Exercises  (Page 3/5)

 Page 3 / 5

A pharmaceutical company makes tranquilizers. It is assumed that the distribution for the length of time they last is approximately normal. Researchers in a hospital used the drug on a random sample of 9 patients. The effective period of the tranquilizer for each patient (in hours) was as follows: 2.7; 2.8; 3.0; 2.3; 2.3; 2.2; 2.8; 2.1; and 2.4 .

• $\overline{x}=\text{________}$
• ${s}_{x}=\text{________}$
• $n=\text{________}$
• $n-1=\text{________}$
• 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 95% confidence interval for the population mean length of time.
• State the confidence interval.
• Sketch the graph.
• Calculate the error bound.
• What does it mean to be “95% confident” in this problem?

Suppose that 14 children were surveyed to determine how long they had to use training wheels. It was revealed that they used them an average of 6 months with a sample standard deviation of 3 months. Assume that the underlying population distribution is normal.

• $\overline{x}=\text{________}$
• ${s}_{x}=\text{________}$
• $n=\text{________}$
• $n-1=\text{________}$
• 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 99% confidence interval for the population mean length of time using training wheels.
• State the confidence interval.
• Sketch the graph.
• Calculate the error bound.
• Why would the error bound change if the confidence level was lowered to 90%?

• 6
• 3
• 14
• 13
• the time for a child to remove his training wheels
• the mean time for 14 children to remove their training wheels.
• ${t}_{\text{13}}$
• CI: (3.58, 8.42)
• EB = 2.42

Insurance companies are interested in knowing the population percent of drivers who always buckle up before riding in a car.

• When designing a study to determine this population proportion, what is the minimum number you would need to survey to be 95% confident that the population proportion is estimated to within 0.03?
• If it was later determined that it was important to be more than 95% confident and a new survey was commissioned, how would that affect the minimum number you would need to survey? Why?

Suppose that the insurance companies did do a survey. They randomly surveyed 400 drivers and found that 320 claimed to always buckle up. We are interested in the population proportion of drivers who claim to always buckle up.

• $x=\text{________}$
• $n=\text{________}$
• $p\text{'}=\text{________}$
• Define the Random Variables $X$ and $P\text{'}$ , in words.
• Which distribution should you use for this problem? Explain your choice.
• Construct a 95% confidence interval for the population proportion that claim to always buckle up.
• State the confidence interval.
• Sketch the graph.
• Calculate the error bound.
• If this survey were done by telephone, list 3 difficulties the companies might have in obtaining random results.

• 320
• 400
• 0.80
• $N\left(0.80,\sqrt{\frac{\left(0.80\right)\left(0.20\right)}{400}}\right)$
• CI: (0.76, 0.84)
• EB = 0.04

Unoccupied seats on flights cause airlines to lose revenue. Suppose a large airline wants to estimate its mean number of unoccupied seats per flight over the past year. To accomplish this, the records of 225 flights are randomly selected and the number of unoccupied seats is noted for each of the sampled flights. The sample mean is 11.6 seats and the sample standard deviation is 4.1 seats.

• $\overline{x}=\text{________}$
• ${s}_{x}=\text{________}$
• $n=\text{________}$
• $n-1=\text{________}$
• Define the Random Variables $X$ and $\overline{X}$ , in words.
• Which distribution should you use for this problem? Explain your choice.
• Construct a 92% confidence interval for the population mean number of unoccupied seats per flight.
• State the confidence interval.
• Sketch the graph.
• Calculate the error bound.

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
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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