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For each problem:

  • In words, define the Random Variable X size 12{X} {} .
  • List the values that X may take on.
  • Give the distribution of X . X ~
Then, answer the questions specific to each individual problem.

Six different colored dice are rolled. Of interest is the number of dice that show a “1.”

  • On average, how many dice would you expect to show a “1”?
  • Find the probability that all six dice show a “1.”
  • Is it more likely that 3 or that 4 dice will show a “1”? Use numbers to justify your answer numerically.
  • X size 12{X} {} = the number of dice that show a 1
  • 0,1,2,3,4,5,6
  • X ~ B ( 6 , 1 6 )
  • 1
  • 0.00002
  • 3 dice

More than 96 percent of the very largest colleges and universities (more than 15,000 total enrollments) have some online offerings. Suppose you randomly pick 13 such institutions. We are interested in the number that offer distance learning courses. (Source: http://en.wikipedia.org/wiki/Distance_education)

  • On average, how many schools would you expect to offer such courses?
  • Find the probability that at most 6 offer such courses.
  • Is it more likely that 0 or that 13 will offer such courses? Use numbers to justify your answer numerically and answer in a complete sentence.

A school newspaper reporter decides to randomly survey 12 students to see if they will attend Tet (Vietnamese New Year) festivities this year. Based on past years, she knows that 18% of students attend Tet festivities. We are interested in the number of students who will attend the festivities.

  • How many of the 12 students do we expect to attend the festivities?
  • Find the probability that at most 4 students will attend.
  • Find the probability that more than 2 students will attend.
  • X size 12{X} {} = the number of students that will attend Tet.
  • 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
  • X ~ B(12,0.18)
  • 2.16
  • 0.9511
  • 0.3702

Suppose that about 85% of graduating students attend their graduation. A group of 22 graduating students is randomly chosen.

  • How many are expected to attend their graduation?
  • Find the probability that 17 or 18 attend.
  • Based on numerical values, would you be surprised if all 22 attended graduation? Justify your answer numerically.

At The Fencing Center, 60% of the fencers use the foil as their main weapon. We randomly survey 25 fencers at The Fencing Center. We are interested in the numbers that do not use the foil as their main weapon.

  • How many are expected to not use the foil as their main weapon?
  • Find the probability that six do not use the foil as their main weapon.
  • Based on numerical values, would you be surprised if all 25 did not use foil as their main weapon? Justify your answer numerically.
  • X size 12{X} {} = the number of fencers that do not use foil as their main weapon
  • 0, 1, 2, 3,... 25
  • X ~ B(25,0.40)
  • 10
  • 0.0442
  • Yes

Approximately 8% of students at a local high school participate in after-school sports all four years of high school. A group of 60 seniors is randomly chosen. Of interest is the number that participated in after-school sports all four years of high school.

  • How many seniors are expected to have participated in after-school sports all four years of high school?
  • Based on numerical values, would you be surprised if none of the seniors participated in after-school sports all four years of high school? Justify your answer numerically.
  • Based upon numerical values, is it more likely that 4 or that 5 of the seniors participated in after-school sports all four years of high school? Justify your answer numerically.

Questions & Answers

if three forces F1.f2 .f3 act at a point on a Cartesian plane in the daigram .....so if the question says write down the x and y components ..... I really don't understand
Syamthanda Reply
hey , can you please explain oxidation reaction & redox ?
Boitumelo Reply
hey , can you please explain oxidation reaction and redox ?
Boitumelo
for grade 12 or grade 11?
Sibulele
the value of V1 and V2
Tumelo Reply
advantages of electrons in a circuit
Rethabile Reply
we're do you find electromagnetism past papers
Ntombifuthi
what a normal force
Tholulwazi Reply
it is the force or component of the force that the surface exert on an object incontact with it and which acts perpendicular to the surface
Sihle
what is physics?
Petrus Reply
what is the half reaction of Potassium and chlorine
Anna Reply
how to calculate coefficient of static friction
Lisa Reply
how to calculate static friction
Lisa
How to calculate a current
Tumelo
how to calculate the magnitude of horizontal component of the applied force
Mogano
How to calculate force
Monambi
a structure of a thermocouple used to measure inner temperature
Anna Reply
a fixed gas of a mass is held at standard pressure temperature of 15 degrees Celsius .Calculate the temperature of the gas in Celsius if the pressure is changed to 2×10 to the power 4
Amahle Reply
How is energy being used in bonding?
Raymond Reply
what is acceleration
Syamthanda Reply
a rate of change in velocity of an object whith respect to time
Khuthadzo
how can we find the moment of torque of a circular object
Kidist
Acceleration is a rate of change in velocity.
Justice
t =r×f
Khuthadzo
how to calculate tension by substitution
Precious Reply
hi
Shongi
hi
Leago
use fnet method. how many obects are being calculated ?
Khuthadzo
khuthadzo hii
Hulisani
how to calculate acceleration and tension force
Lungile Reply
you use Fnet equals ma , newtoms second law formula
Masego
please help me with vectors in two dimensions
Mulaudzi Reply
how to calculate normal force
Mulaudzi
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Source:  OpenStax, Collaborative statistics using spreadsheets. OpenStax CNX. Jan 05, 2016 Download for free at http://legacy.cnx.org/content/col11521/1.23
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