<< Chapter < Page Chapter >> Page >
This module provides a number of homework/review problems related to Continuous Random Variables.

[link][link] refer to the following study: A recent study of mothers of junior high school children in Santa Clara County reported that 76% of the mothers are employed in paid positions. Of those mothers who are employed, 64% work full-time (over 35 hours per week), and 36% work part-time. However, out of all of the mothers in the population, 49% work full-time. The population under study is made up of mothers of junior high school children in Santa Clara County.

Let E = size 12{E={}} {} employed, Let F = size 12{F={}} {} full-time employment

  • Find the percent of all mothers in the population that NOT employed.
  • Find the percent of mothers in the population that are employed part-time.
  • 24%
  • 27%
Got questions? Get instant answers now!

The type of employment is considered to be what type of data?

Qualitative

Got questions? Get instant answers now!

Find the probability that a randomly selected mother works part-time given that she is employed.

0.36

Got questions? Get instant answers now!

Find the probability that a randomly selected person from the population will be employed OR work full-time.

0.7636

Got questions? Get instant answers now!

Based upon the above information, are being employed AND working part-time:

  • mutually exclusive events? Why or why not?
  • independent events? Why or why not?
  • No,
  • No,
Got questions? Get instant answers now!

[link] - [link] refer to the following: We randomly pick 10 mothers from the above population. We are interested in the number of the mothers that are employed. Let X = size 12{X={}} {} number of mothers that are employed.

State the distribution for X size 12{X} {} .

B ( 10 , 0 . 76 ) size 12{B \( "10",0 "." "76" \) } {}

Got questions? Get instant answers now!

Find the probability that at least 6 are employed.

0.9330

Got questions? Get instant answers now!

We expect the Statistics Discussion Board to have, on average, 14 questions posted to it per week. We are interested in the number of questions posted to it per day.

  • Define X size 12{X} {} .
  • What are the values that the random variable may take on?
  • State the distribution for X size 12{X} {} .
  • Find the probability that from 10 to 14 (inclusive) questions are posted to the Listserv on a randomly picked day.
  • X = size 12{X={}} {} the number of questions posted to the Statistics Listserv per day
  • x = 0,1,2, . . . size 12{x=0,1,2, "." "." "." } {}
  • X ~ P ( 2 ) size 12{X "~" P \( 2 \) } {}
  • 0
Got questions? Get instant answers now!

A person invests $1000 in stock of a company that hopes to go public in 1 year.

  • The probability that the person will lose all his money after 1 year (i.e. his stock will be worthless) is 35%.
  • The probability that the person’s stock will still have a value of $1000 after 1 year (i.e. no profit and no loss) is 60%.
  • The probability that the person’s stock will increase in value by $10,000 after 1 year (i.e. will be worth $11,000) is 5%.

Find the expected PROFIT after 1 year.

$150

Got questions? Get instant answers now!

Rachel’s piano cost $3000. The average cost for a piano is $4000 with a standard deviation of $2500. Becca’s guitar cost $550. The average cost for a guitar is $500 with a standard deviation of $200.Matt’s drums cost $600. The average cost for drums is $700 with a standard deviation of $100. Whose cost was lowest when compared to his or her own instrument? Justify your answer.

Matt

Got questions? Get instant answers now!
Horizontal boxplot with first whisker extending from 1 to 2, box from 2 to 5,  line at 4, and second whisker extending from 5 to 7.

For each statement below, explain why each is either true or false.

  • 25% of the data are at most 5.
  • There is the same amount of data from 4 – 5 as there is from 5 – 7.
  • There are no data values of 3.
  • 50% of the data are 4.
  • False
  • True
  • False
  • False
Got questions? Get instant answers now!

[link][link] refer to the following: 64 faculty members were asked the number of cars they owned (including spouse and children’s cars). The results are given in the following graph: Histogram consisting of 5 bars with number of cars, from 0-7 in increments of 1, on the x-axis, and frequency, in increments of 0.1 from 0.15-0.45, on the y-axis. No bars exist for 4, 5, or 7. Bar 0 has a frequency of 0.075, 1 has 0.15, 2 has 0.45, 3 has 0.25, and 6 has 0.075.

Find the approximate number of responses that were “3.”

16

Got questions? Get instant answers now!

Find the first, second and third quartiles. Use them to construct a box plot of the data.

2,2,3 size 12{2,2,3} {}

Got questions? Get instant answers now!

[link][link] refer to the following study done of the Girls soccer team “Snow Leopards”:

Hair Style Hair Color
blond brown black
ponytail 3 2 5
plain 2 2 1
Suppose that one girl from the Snow Leopards is randomly selected.

Find the probability that the girl has black hair GIVEN that she wears a ponytail.

5 10 = 0 . 5 size 12{ { {5} over {"10"} } =0 "." 5} {}

Got questions? Get instant answers now!

Find the probability that the girl wears her hair plain OR has brown hair.

7 15 size 12{ { {7} over {"15"} } } {}

Got questions? Get instant answers now!

Find the probability that the girl has blond hair AND that she wears her hair plain.

2 15 size 12{ { {2} over {"15"} } } {}

Got questions? Get instant answers now!

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
Got questions? Join the online conversation and get instant answers!
Jobilize.com Reply

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Collaborative statistics. OpenStax CNX. Jul 03, 2012 Download for free at http://cnx.org/content/col10522/1.40
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Collaborative statistics' conversation and receive update notifications?

Ask