(Problem 1: Ceiling of an Exponential)
 
(47 intermediate revisions by 24 users not shown)
Line 1: Line 1:
 +
[[Category:ECE302Fall2008_ProfSanghavi]]
 +
[[Category:probabilities]]
 +
[[Category:ECE302]]
 +
[[Category:homework]]
 +
[[Category:problem solving]]
 +
 
== Instructions ==
 
== Instructions ==
 
Homework 6 can be [https://engineering.purdue.edu/ece302/homeworks/HW6FA08.pdf downloaded here] on the [https://engineering.purdue.edu/ece302/ ECE 302 course website].
 
Homework 6 can be [https://engineering.purdue.edu/ece302/homeworks/HW6FA08.pdf downloaded here] on the [https://engineering.purdue.edu/ece302/ ECE 302 course website].
Line 6: Line 12:
  
 
         <math>\mathrm{ceil}(a)</math> = <math>a</math> if <math>a</math> is an integer
 
         <math>\mathrm{ceil}(a)</math> = <math>a</math> if <math>a</math> is an integer
              = the smallest integer bigger than <math>a</math> if <math>a</math> is not an integer
+
                = the smallest integer bigger than <math>a</math> if <math>a</math> is not an integer
  
 
What is the PMF of <math>Y</math>? Is it one of the common random variables?  (Hint: for all <math>k</math>, find the quantity <math>P(Y > k)</math>. Then find the PMF)
 
What is the PMF of <math>Y</math>? Is it one of the common random variables?  (Hint: for all <math>k</math>, find the quantity <math>P(Y > k)</math>. Then find the PMF)
 +
 +
*[[Tiffany Sukwanto 6.1_ECE302Fall2008sanghavi]]
 +
 +
*[[Joshua Long 6.1_ECE302Fall2008sanghavi]]
 +
 +
*[[Justin Mauck 6.1_ECE302Fall2008sanghavi]]
 +
 +
== Problem 2: Fair Wages ==
 +
``I do not have problems with anyone earning above average, as long as no one earns below average." - a quote (mistakenly attributed to) Max Weber. Can such a situation occur? Justify your answer.
 +
 +
*[[Brian Thomas 6.2_ECE302Fall2008sanghavi]] One possible solution
 +
*[[Gregory Pajot 6.2_ECE302Fall2008sanghavi]]
 +
*[[Virgil Hsieh 6.2_ECE302Fall2008sanghavi]]
 +
*[[Zhongtian Wang 6.2_ECE302Fall2008sanghavi]]
 +
*[[Michael Allen 6.2_ECE302Fall2008sanghavi]]
 +
*[[Christopher Wacnik 6.2_ECE302Fall2008sanghavi]]
 +
*[[Sahil Khosla 6.2_ECE302Fall2008sanghavi]]
 +
*[[AJ Hartnett 6.2 --Different answer than above!_ECE302Fall2008sanghavi]]
 +
*[[Jaewoo Choi 6.2_ECE302Fall2008sanghavi]]
 +
 +
== Problem 3: An Uncommon PDF ==
 +
Let <math>Y</math> be a random variable with probability density function (PDF)
 +
 +
<math>
 +
f_Y(v) = \left\{\begin{array}{ll}
 +
1 + v,& -1\leq v\leq0,\\
 +
v,& 0<v\leq1,\\
 +
0,& \mbox{otherwise}.
 +
\end{array}\right.</math>
 +
 +
Find
 +
*(a) <math>P(|Y| < 1/2)</math>
 +
*(b) <math>P(Y > 0|Y < 1/2)</math>
 +
*(c) <math>E[Y]</math>.
 +
 +
*[[Anand Gautam 6.3_ECE302Fall2008sanghavi]]
 +
 +
*[[Nicholas Browdues 6.3_ECE302Fall2008sanghavi]]
 +
*[[Hamad AL Shehhi_ECE302Fall2008sanghavi]]
 +
 +
*[[Ken Pesyna_ECE302Fall2008sanghavi]]
 +
 +
*[[Kunal Kapoor 6.3_ECE302Fall2008sanghavi]]
 +
 +
*[[Monsu Mathew 6.3_ECE302Fall2008sanghavi]]
 +
 +
== Problem 4: Gaussian Coordinates ==
 +
A random point <math>(X,Y)</math> on a plane is chosen as follows: <math>X</math> and <math>Y</math> are chosen independently, with each one being a Gaussian random variable with zero mean and variance of 1. Let <math>D</math> be the square of the (random) distance of the point from the center.  Find the PDF of <math>D</math>. Is <math>D</math> one of the common random variables?
 +
 +
*[[Katie Pekkarinen 6.4_ECE302Fall2008sanghavi]]
 +
 +
*[[Divyanshu Kamboj 6.4_ECE302Fall2008sanghavi]]
 +
 +
*[[Umang Jhunjhunwala 6.4_ECE302Fall2008sanghavi]]
 +
 +
*[[Spencer Mitchell 6.4_ECE302Fall2008sanghavi]]
 +
 +
*[[Steven Streeter 6.4_ECE302Fall2008sanghavi]]
 +
----
 +
[[Main_Page_ECE302Fall2008sanghavi|Back to ECE302 Fall 2008 Prof. Sanghavi]]

Latest revision as of 11:57, 22 November 2011


Instructions

Homework 6 can be downloaded here on the ECE 302 course website.

Problem 1: Ceiling of an Exponential

$ X $ is an exponential random variable with paramter $ \lambda $. $ Y = \mathrm{ceil}(X) $, where the ceiling function $ \mathrm{ceil}(\cdot) $ rounds its argument up to the closest integer, i.e.:

        $ \mathrm{ceil}(a) $ = $ a $ if $ a $ is an integer
               = the smallest integer bigger than $ a $ if $ a $ is not an integer

What is the PMF of $ Y $? Is it one of the common random variables? (Hint: for all $ k $, find the quantity $ P(Y > k) $. Then find the PMF)

Problem 2: Fair Wages

``I do not have problems with anyone earning above average, as long as no one earns below average." - a quote (mistakenly attributed to) Max Weber. Can such a situation occur? Justify your answer.

Problem 3: An Uncommon PDF

Let $ Y $ be a random variable with probability density function (PDF)

$ f_Y(v) = \left\{\begin{array}{ll} 1 + v,& -1\leq v\leq0,\\ v,& 0<v\leq1,\\ 0,& \mbox{otherwise}. \end{array}\right. $

Find

  • (a) $ P(|Y| < 1/2) $
  • (b) $ P(Y > 0|Y < 1/2) $
  • (c) $ E[Y] $.

Problem 4: Gaussian Coordinates

A random point $ (X,Y) $ on a plane is chosen as follows: $ X $ and $ Y $ are chosen independently, with each one being a Gaussian random variable with zero mean and variance of 1. Let $ D $ be the square of the (random) distance of the point from the center. Find the PDF of $ D $. Is $ D $ one of the common random variables?


Back to ECE302 Fall 2008 Prof. Sanghavi

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang