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

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
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
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
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 did you get the value of 2000N.What calculations are needed to arrive at it
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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.