Yahoo Canada Web Search

Search results

  1. (i)The expected value (or mean) E(X). (ii)The variance V(X). (iii)The cumulative distribution function F(x). You will learn what these words mean shortly. Lecture 6 : Discrete Random Variables and Probability Distributions

    • 332KB
    • 33
  2. of the observations (mean, sd, etc.) is also a random variable •Thus, any statistic, because it is a random variable, has a probability distribution - referred to as a sampling distribution •Let’s focus on the sampling distribution of the mean,! X

    • 849KB
    • 31
  3. p(:) can mean di erent things depending on the context p(X) denotes the distribution (PMF/PDF) of an r.v. X p(X = x) or p(x) denotes the probability or probability density at point x Actual meaning should be clear from the context (but be careful) Exercise the same care when p(:) is a speci c distribution (Bernoulli, Beta, Gaussian, etc.)

    • 1MB
    • 37
  4. The sample space is effectively forgotten. (In other words, you wouldn’t be able to tell the difference between a fair coin and a Bernoulli random variable taking a value of 1 when the coin lands heads-up after being flipped, or a fair die being rolled and a Bernoulli random variable taking a value of 1 when the number rolled is even.) Example 1

    • Normal?
    • Why the Normal?
    • Linear transformations of Normal RVs
    • Computing probabilities with Normal RVs
    • Computing probabilities with Normal RVs: Old school

    Part statement into a random variable In situations with probability distributions heights? one classroom. Fits perfectly! But what about in another classroom?

    Common for natural phenomena: height, weight, etc. Most noise in the world is Often results Actually log-normal Normal because from the sum of many it’s random variables • Sample easy

    Let ~ , % with CDF ≤ = . Linear transformations of X are also Normal. If = + , then ~ + , Proof: = = + = + Var

    Let ~ , % . To compute the CDF, ≤ = : We cannot analytically solve the integral (it has no closed form) ...but we can solve numerically using a function Φ: − = Φ CDF of the Standard Normal,

    *particularly useful when we have closed book exams with no calculator** **we have open book exams with calculators this quarter Knowing how to use a Standard Normal Table will still be useful in our understanding of Normal RVs. Let ~ , % . What is Rewrite in terms of standard normal CDF Linear transforms of Normals are Normal: Then, look up in a S...

  5. Oct 23, 2020 · Around 99.7% of values are within 3 standard deviations from the mean. Example: Using the empirical rule in a normal distribution You collect SAT scores from students in a new test preparation course. The data follows a normal distribution with a mean score (M) of 1150 and a standard deviation (SD) of 150. Following the empirical rule:

  6. People also ask

  7. The sample space is the set of all possible outcomes of the experiment. We usually call it S. It is important to be able to list the outcomes clearly. For example, if I plant ten bean seeds and count the number that germinate, the sample space is S ={0,1,2,3,4,5,6,7,8,9,10}. If I toss a coin three times and record the result, the sample space is