# 9.15 Homework  (Page 8/8)

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The next two questions refer to the following information: Over the past few decades, public health officials have examined the link between weight concerns and teen girls smoking. Researchers surveyed a group of 273 randomly selected teen girls living in Massachusetts (between 12 and 15 years old). After four years the girls were surveyed again. Sixty-three (63) said they smoked to stay thin. Is there good evidence that more than thirty percent of the teen girls smoke to stay thin?

The alternate hypothesis is

• $p<0\text{.}\text{30}$
• $p\le 0\text{.}\text{30}$
• $p\ge 0\text{.}\text{30}$
• $p>0\text{.}\text{30}$

D

After conducting the test, your decision and conclusion are

• Reject ${H}_{o}$ : There is sufficient evidence to conclude that more than 30% of teen girls smoke to stay thin.
• Do not reject ${H}_{o}$ : There is not sufficient evidence to conclude that less than 30% of teen girls smoke to stay thin.
• Do not reject ${H}_{o}$ : There is not sufficient evidence to conclude that more than 30% of teen girls smoke to stay thin.
• Reject ${H}_{o}$ : There is sufficient evidence to conclude that less than 30% of teen girls smoke to stay thin.

C

The next three questions refer to the following information: A statistics instructor believes that fewer than 20% of Evergreen Valley College (EVC) students attended the opening night midnight showing of the latest Harry Potter movie. She surveys 84 of her students and finds that 11 of attended the midnight showing.

An appropriate alternative hypothesis is

• $p=0\text{.}\text{20}$
• $p>0\text{.}\text{20}$
• $p<0\text{.}\text{20}$
• $p\le 0\text{.}\text{20}$

C

At a 1% level of significance, an appropriate conclusion is:

• There is insufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is less than 20%.
• There is sufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is more than 20%.
• There is sufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is less than 20%.
• There is insufficient evidence to conclude that the percent of EVC students that attended the midnight showing of Harry Potter is at least 20%.

A

The Type I error is to conclude that the percent of EVC students who attended is

• at least 20%, when in fact, it is less than 20%.
• 20%, when in fact, it is 20%.
• less than 20%, when in fact, it is at least 20%.
• less than 20%, when in fact, it is less than 20%.

C

The next two questions refer to the following information:

It is believed that Lake Tahoe Community College (LTCC) Intermediate Algebra students get less than 7 hours of sleep per night, on average. A survey of 22 LTCC Intermediate Algebra students generated a mean of 7.24 hours with a standard deviation of 1.93 hours. At a level of significance of 5%, do LTCC Intermediate Algebra students get less than 7 hours of sleep per night, on average?

The distribution to be used for this test is $\overline{X}$ ~

• $N\left(7\text{.}\text{24},\frac{1\text{.}\text{93}}{\sqrt{\text{22}}}\right)$
• $N\left(7\text{.}\text{24},1\text{.}\text{93}\right)$
• ${t}_{\text{22}}$
• ${t}_{\text{21}}$

D

The Type II error is to not reject that the mean number of hours of sleep LTCC students get per night is at least 7 when, in fact, the mean number of hours

• is more than 7 hours.
• is at most 7 hours.
• is at least 7 hours.
• is less than 7 hours.

D

The next three questions refer to the following information: Previously, an organization reported that teenagers spent 4.5 hours per week, on average, on the phone. The organization thinks that, currently, the mean is higher. Fifteen (15) randomly chosen teenagers were asked how many hours per week they spend on the phone. The sample mean was 4.75 hours with a sample standard deviation of 2.0. Conduct a hypothesis test.

The null and alternate hypotheses are:

• ${H}_{o}:\overline{x}=4\text{.}5$ , ${H}_{a}:\overline{x}>4\text{.}5$
• ${H}_{o}:\mu \ge 4\text{.}5$ ${H}_{a}:\mu <4\text{.}5$
• ${H}_{o}:\mu =4\text{.}\text{75}$ ${H}_{a:}\mu >4\text{.}\text{75}$
• ${H}_{o}:\mu =4\text{.}5$ ${H}_{a}:\mu >4\text{.}5$

D

At a significance level of $a=0\text{.}\text{05}$ , what is the correct conclusion?

• There is enough evidence to conclude that the mean number of hours is more than 4.75
• There is enough evidence to conclude that the mean number of hours is more than 4.5
• There is not enough evidence to conclude that the mean number of hours is more than 4.5
• There is not enough evidence to conclude that the mean number of hours is more than 4.75

C

The Type I error is:

• To conclude that the current mean hours per week is higher than 4.5, when in fact, it is higher.
• To conclude that the current mean hours per week is higher than 4.5, when in fact, it is the same.
• To conclude that the mean hours per week currently is 4.5, when in fact, it is higher.
• To conclude that the mean hours per week currently is no higher than 4.5, when in fact, it is not higher.

B

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
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
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
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
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?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
1 It is estimated that 30% of all drivers have some kind of medical aid in South Africa. What is the probability that in a sample of 10 drivers: 3.1.1 Exactly 4 will have a medical aid. (8) 3.1.2 At least 2 will have a medical aid. (8) 3.1.3 More than 9 will have a medical aid.