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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

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 (random) distance of the point from the center. Find the PDF of $ D $. Is $ D $ one of the common random variables?

Alumni Liaison

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

Buyue Zhang