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10.1 Homework  (Page 6/7)

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Try these multiple choice questions.

For questions [link] – [link] , use the following information.

A new AIDS prevention drugs was tried on a group of 224 HIV positive patients. Forty-five (45) patients developed AIDS after four years. In a control group of 224 HIV positive patients, 68 developed AIDS after four years. We want to test whether the method of treatment reduces the proportion of patients that develop AIDS after four years or if the proportions of the treated group and the untreated group stay the same.

Let the subscript t size 12{t} {} = treated patient and ut size 12{ ital "ut"} {} = untreated patient.

The appropriate hypotheses are:

  • H o : p t < p ut size 12{H rSub { size 8{o} } :p rSub { size 8{t} }<p rSub { size 8{ ital "ut"} } } {} and H a : p t ≥ p ut size 12{H rSub { size 8{a} } :p rSub { size 8{t} }>= p rSub { size 8{ ital "ut"} } } {}
  • H o : p t ≤ p ut size 12{H rSub { size 8{o} } :p rSub { size 8{t} }<= p rSub { size 8{ ital "ut"} } } {} and H a : p t > p ut size 12{H rSub { size 8{a} } :p rSub { size 8{t} }>p rSub { size 8{ ital "ut"} } } {}
  • H o : p t = p ut size 12{H rSub { size 8{o} } :p rSub { size 8{t} } =p rSub { size 8{ ital "ut"} } } {} and H a : p t ≠ p ut size 12{H rSub { size 8{a} } :p rSub { size 8{t} }<>p rSub { size 8{ ital "ut"} } } {}
  • H o : p t = p ut size 12{H rSub { size 8{o} } :p rSub { size 8{t} } =p rSub { size 8{ ital "ut"} } } {} and H a : p t < p ut size 12{H rSub { size 8{a} } :p rSub { size 8{t} }<p rSub { size 8{ ital "ut"} } } {}

D

If the p -value is 0.0062 what is the conclusion (use α = 0.05 size 12{α=5%} {} )?

  • The method has no effect.
  • There is sufficient evidence to conclude that the method reduces the proportion of HIV positive patients that develop AIDS after four years.
  • There is sufficient evidence to conclude that the method increases the proportion of HIV positive patients that develop AIDS after four years.
  • There is insufficient evidence to conclude that the method reduces the proportion of HIV positive patients that develop AIDS after four years.

B

Lesley E. Tan investigated the relationship between left-handedness and right-handedness and motor competence in preschool children. Random samples of 41 left-handers and 41 right-handers were given several tests of motor skills to determine if there is evidence of a difference between the children based on this experiment. The experiment produced the means and standard deviations shown below. Determine the appropriate test and best distribution to use for that test.

Left-handed Right-handed
Sample size 41 41
Sample mean 97.5 98.1
Sample standard deviation 17.5 19.2

  • Two independent means, normal distribution
  • Two independent means, student's-t distribution
  • Matched or paired samples, student's-t distribution
  • Two population proportions, normal distribution

B

For questions [link] – [link] , use the following information.

An experiment is conducted to show that blood pressure can be consciously reduced in people trained in a “biofeedback exercise program.” Six (6) subjects were randomly selected and the blood pressure measurements were recorded before and after the training. The difference between blood pressures was calculated after − before size 12{ left ( ital "after" - ital "before" right )} {} producing the following results: x ¯ d = − 10 . 2 size 12{ {overline {x}} rSub { size 8{d} } = - "10" "." 2} {} s d = 8 . 4 size 12{s rSub { size 8{d} } =8 "." 4} {} . Using the data, test the hypothesis that the blood pressure has decreased after the training,

The distribution for the test is

  • t 5 size 12{t rSub { size 8{5} } } {}
  • t 6 size 12{t rSub { size 8{6} } } {}
  • N ( − 10 . 2,8 . 4 ) size 12{N \( - "10" "." 2,8 "." 4 \) } {}
  • N ( − 10 . 2, 8 . 4 6 ) size 12{N \( - "10" "." 2, { { size 8{8 "." 4} } over { size 8{ sqrt {6} } } } \) } {}

A

If α = 0 . 05 size 12{a=0 "." "05"} {} , the p size 12{p} {} -value and the conclusion are

  • 0.0014; There is sufficient evidence to conclude that the blood pressure decreased after the training
  • 0.0014; There is sufficient evidence to conclude that the blood pressure increased after the training
  • 0.0155; There is sufficient evidence to conclude that the blood pressure decreased after the training
  • 0.0155; There is sufficient evidence to conclude that the blood pressure increased after the training

C

For questions [link] – [link] , use the following information.

Questions & Answers

how does Neisseria cause meningitis
Nyibol Reply
what is microbiologist
Muhammad Reply
what is errata
Muhammad
is the branch of biology that deals with the study of microorganisms.
Ntefuni Reply
What is microbiology
Mercy Reply
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
Ziyad Reply
How bacteria create energy to survive?
Muhamad Reply
Bacteria doesn't produce energy they are dependent upon their substrate in case of lack of nutrients they are able to make spores which helps them to sustain in harsh environments
_Adnan
But not all bacteria make spores, l mean Eukaryotic cells have Mitochondria which acts as powerhouse for them, since bacteria don't have it, what is the substitution for it?
Muhamad
they make spores
Louisiaste
what is sporadic nd endemic, epidemic
Aminu Reply
the significance of food webs for disease transmission
Abreham
food webs brings about an infection as an individual depends on number of diseased foods or carriers dully.
Mark
explain assimilatory nitrate reduction
Esinniobiwa Reply
Assimilatory nitrate reduction is a process that occurs in some microorganisms, such as bacteria and archaea, in which nitrate (NO3-) is reduced to nitrite (NO2-), and then further reduced to ammonia (NH3).
Elkana
This process is called assimilatory nitrate reduction because the nitrogen that is produced is incorporated in the cells of microorganisms where it can be used in the synthesis of amino acids and other nitrogen products
Elkana
Examples of thermophilic organisms
Shu Reply
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
Micheal Reply
Prevent foreign microbes to the host
Abubakar
they provide healthier benefits to their hosts
ayesha
They are friends to host only when Host immune system is strong and become enemies when the host immune system is weakened . very bad relationship!
Mark
what is cell
faisal Reply
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
ok
Innocent
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
Micheal Reply
There are nothing like emergency disease but there are some common medical emergency which can occur simultaneously like Bleeding,heart attack,Breathing difficulties,severe pain heart stock.Hope you will get my point .Have a nice day ❣️
_Adnan
define infection ,prevention and control
Innocent
I think infection prevention and control is the avoidance of all things we do that gives out break of infections and promotion of health practices that promote life
Lubega
Heyy Lubega hussein where are u from?
_Adnan
en français
Adama
which site have a normal flora
ESTHER Reply
Many sites of the body have it Skin Nasal cavity Oral cavity Gastro intestinal tract
Safaa
skin
Asiina
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
all
Tesfaye
by fussion
Asiina
what are the advantages of normal Flora to the host
Micheal
what are the ways of control and prevention of nosocomial infection in the hospital
Micheal
what is inflammation
Shelly Reply
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Micheal Reply
Binomial nomenclature
adeolu
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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
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