10-17-07 - according to rules of probabilities Probability...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Standard Normal Tables An internal probability distribution gives probability that random variable, X, will be between to given values. P(x 1 < X < x 2 ) P(Z < z) … z will take on some value less than z P(z 1 < Z < z 2 ) = P(Z < z 2 ) – P(Z<z) Steps in Solving Normal Probability Problems 1. Write down information about random variable i.e. x 2 (μ,σ) 2. Draw picture of problem and write down the probability statement. Ex. P(x>30) 3. Transform value of X into Z values. Example 3.22 μ = $350 σ = $240 P(z) = $4000 Z = 4000 – 3500 = 2.08 240 (Go to the Table) P(z>4000) = 1-P(z<4000) = 1-.98 = .0188 or 18.8% General Addition Rule Conditional Probability General Multiplication Rule Statistical Independence Or P(A/B) = P(A)
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Parameters When Purchase will be made a) P(a) = b) P(b) = 90 + 530 – 56 = 564 = 58% 978 978 c) 34 + 156 = 190 978 978 Random Variables – a random variable is a quantitative variable whose value varies
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: according to rules of probabilities Probability Distribution of Random Variables The probability distribution of random variable x, p(a) gives the probability that the random variable will take on each of possible values. Sampling Distribution and Confidence Interval Point Estimators Biased Sample does not represent all characteristics of population Point Estimate vs. Interval Estimate Statistic describes sample Parameter describes population Point Estimates Mean, standard deviation, mode, and median. v/x Type of Computer 0-3m 3-6m 6-12m Total Notebook 34 15 258 448 Desktop 56 346 128 530 Total 90 592 386 978 S Point estimate for quantitative variables. Comparing two populations Comparing mean and variances __ __ 1 2 X 1 X 2 Common Point Estimator 1 2----- = 1 2 1...
View Full Document

This note was uploaded on 04/18/2008 for the course ECON 205 taught by Professor Diagne during the Fall '07 term at Towson.

Page1 / 3

10-17-07 - according to rules of probabilities Probability...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online