Discrete Random Variables: Practice 2: Binomial Distribution
1.9
2008/05/30 16:57:22 GMT-5
2008/10/27 14:29:02.110 GMT-5
Susan
Dean
deansusan@deanza.edu
Barbara
Illowsky
illowskybarbara@deanza.edu
Susan
Dean
deansusan@deanza.edu
Barbara
Illowsky
illowskybarbara@deanza.edu
Connexions
cnx@cnx.org
This module provides a practice of Binomial Distribution as a part of Collaborative Statistics collection (col10522) by Barbara Illowsky and Susan Dean.
Student Learning Outcomes
- The student will practice constructing Binomial Distributions.
Given
The Higher Education Research Institute at UCLA surveyed more than 263,000 incoming
freshmen from 385 colleges. 36.7% of first-generation college students expected to work fulltime
while in college. (Source: Eric Hoover, The Chronicle of Higher Education, 2/3/2006). Suppose that you randomly pick 8 college freshmen from the survey. You are interested in the number that expect to work full-time while in college.
Interpret the Data
In words, define the random Variable X.
X
= the number that expect to work full-time.
X
~___________
B
(8,0.367)
What values does
X
take on?
0,1,2,3,4,5,6,7,8
Construct the probability distribution function (PDF) for
X
.
On average
(
u
)
, how many would you expect to answer yes?
2.94
What is the standard deviation
(
σ
)
?
1.36
What is the probability what at most 5 of the freshmen expect to work full-time?
0.9677
What is the probability that at least 2 of the freshmen expect to work full-time?
0.8547
Construct a histogram or plot a line graph. Label the horizontal and vertical axes with words. Include numerical scaling.