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- Contingency tables (modified r
This module introduces the contingency table as a way of determining conditional probabilities.
A
contingency table provides a different way of calculating probabilities. The table helps in determining conditional probabilities quite easily. The table displays sample values in relation to two different variables that may be dependent or contingent on one another. Later on, we will use contingency tables again, but in another manner.
Suppose a study of speeding violations and drivers who use car phones produced the following fictional data:
|
Speeding violation
in the last year |
No speeding violation
in the last year |
Total |
Car phone user |
25 |
280 |
305 |
Not a car phone user |
45 |
405 |
450 |
Total |
70 |
685 |
755 |
The total number of people in the sample is 755. The row totals are 305 and 450. The column totals are 70 and 685. Notice that
and
.
Calculate the following probabilities using the table
(The sample space is reduced to the number of persons who had a violation.)
(The sample space is reduced to the number of persons who were not car phone users.)
The following table shows a random sample of 100 hikers and the areas of hiking preferred:
Hiking area preference
Sex |
The Coastline |
Near Lakes and Streams |
On Mountain Peaks |
Total |
Female |
18 |
16 |
___ |
45 |
Male |
___ |
___ |
14 |
55 |
Total |
___ |
41 |
___ |
___ |
Hiking area preference
Sex |
The Coastline |
Near Lakes and Streams |
On Mountain Peaks |
Total |
Female |
18 |
16 |
11 |
45 |
Male |
16 |
25 |
14 |
55 |
Total |
34 |
41 |
25 |
100 |
Are the events "being female" and "preferring the coastline" independent events?
Let
= being female and let
= preferring the coastline.
-
A
=
-
B
=
Are these two numbers the same? If they are, then
and
are independent. If they are not, then
and
are not independent.
-
A
-
B
, so the events
and
are not independent.
Find the probability that a person is male given that the person prefers hiking near lakes and streams. Let
= being male and let
= prefers hiking near lakes and streams.
-
A
What word tells you this is a conditional?
-
B
Fill in the blanks and calculate the probability:
.
-
C
Is the sample space for this problem all 100 hikers? If not, what is it?
-
A
The word 'given' tells you that this is a conditional.
-
B
-
C
No, the sample space for this problem is 41.
Find the probability that a person is female or prefers hiking on mountain peaks.
Let
= being female and let
= prefers mountain peaks.
-
A
-
B
-
C
-
D
Therefore,
-
A
-
B
-
C
-
D
Questions & Answers
how does Neisseria cause meningitis
is the branch of biology that deals with the study of microorganisms.
studies of microbes
Louisiaste
when we takee the specimen which lumbar,spin,
How bacteria create energy to survive?
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
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
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
Give Examples of thermophilic organisms
Shu
advantages of normal Flora to the host
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
cell is the smallest unit of life
Fauziya
cell is the smallest unit of life
Akanni
cell is the structural and functional unit of life
Hasan
is the fundamental units of Life
Musa
what are emergency diseases
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
which site have a normal flora
Many sites of the body have it
Skin
Nasal cavity
Oral cavity
Gastro intestinal tract
Safaa
skin,Oral,Nasal,GIt
Sadik
How can Commensal can Bacteria change into pathogen?
Sadik
How can Commensal Bacteria change into pathogen?
Sadik
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
part of a tissue or an organ being wounded or bruised.
Wilfred
what term is used to name and classify microorganisms?
Binomial nomenclature
adeolu
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Source:
OpenStax, Collaborative statistics: custom version modified by r. bloom. OpenStax CNX. Nov 15, 2010 Download for free at http://legacy.cnx.org/content/col10617/1.4
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