The Standard Normal Distribution Section 5.2. The Standard Score The standard score, or z-score, represents the number of standard deviations a random.

Slides:



Advertisements
Similar presentations
5.1 Normal Probability Distributions Normal distribution A continuous probability distribution for a continuous random variable, x. The most important.
Advertisements

5 Normal Probability Distributions
Normal Probability Distributions
Normal Probability Distributions 1 Chapter 5. Chapter Outline Introduction to Normal Distributions and the Standard Normal Distribution 5.2 Normal.
Section 5.1 Introduction to Normal Distributions and the Standard Normal Distribution.
How do I use normal distributions in finding probabilities?
Normal Distributions: Finding Values
Normal Distributions Review
BCOR 1020 Business Statistics Lecture 13 – February 28, 2008.
Chapter 6: Probability.
Unit 5 Data Analysis.
Section 5.4 Normal Distributions Finding Values.
Normal Probability Distributions 1. Section 1 Introduction to Normal Distributions 2.
§ 5.2 Normal Distributions: Finding Probabilities.
Chapter Six Normal Curves and Sampling Probability Distributions.
7.3 APPLICATIONS OF THE NORMAL DISTRIBUTION. PROBABILITIES We want to calculate probabilities and values for general normal probability distributions.
Section 6.3 Finding Probability Using the Normal Curve HAWKES LEARNING SYSTEMS math courseware specialists Copyright © 2008 by Hawkes Learning Systems/Quant.
Chapter Normal Probability Distributions 1 of © 2012 Pearson Education, Inc. All rights reserved. Edited by Tonya Jagoe.
Chapter 6 Normal Probability Distribution Lecture 1 Sections: 6.1 – 6.2.
Chapter 6.1 Normal Distributions. Distributions Normal Distribution A normal distribution is a continuous, bell-shaped distribution of a variable. Normal.
Normal Probability Distributions Larson/Farber 4th ed 1.
Normal Distributions.  Symmetric Distribution ◦ Any normal distribution is symmetric Negatively Skewed (Left-skewed) distribution When a majority of.
§ 5.4 Normal Distributions: Finding Values. Finding z-Scores Example : Find the z - score that corresponds to a cumulative area of z
Table A & Its Applications - The entry in Table A - Table A’s entry is an area underneath the curve, to the left of z Table A’s entry is a proportion of.
Copyright © 2013, 2009, and 2007, Pearson Education, Inc. Chapter 6 Probability Distributions Section 6.2 Probabilities for Bell-Shaped Distributions.
AP Review #3: Continuous Probability (The Normal Distribution)
The Normal Distribution
Normal Distributions: Finding Values Larson/Farber 4th ed1.
§ 5.3 Normal Distributions: Finding Values. Probability and Normal Distributions If a random variable, x, is normally distributed, you can find the probability.
Chapter 5 Review. Find the area of the indicated region under the standard normal curve. Use the table and show your work. Find the areas to the left.
Chapter 5 Normal Probability Distributions 1 Larson/Farber 4th ed.
What does a population that is normally distributed look like? X 80  = 80 and  =
© 2010 Pearson Prentice Hall. All rights reserved Chapter The Normal Probability Distribution © 2010 Pearson Prentice Hall. All rights reserved 3 7.
EXAMPLE 3 Use a z-score and the standard normal table Scientists conducted aerial surveys of a seal sanctuary and recorded the number x of seals they observed.
Normal Probability Distributions Chapter 5. § 5.1 Introduction to Normal Distributions and the Standard Distribution.
Section 5.1 Discrete Probability. Probability Distributions x P(x)1/4 01/83/8 x12345 P(x)
Copyright © 2015, 2012, and 2009 Pearson Education, Inc. 1 Chapter Normal Probability Distributions 5.
Copyright © 2015, 2012, and 2009 Pearson Education, Inc. 1 Chapter Normal Probability Distributions 5.
Normal Probability Distributions. Intro to Normal Distributions & the STANDARD Normal Distribution.
Unit 6 Section : Normal Distributions: Finding Probabilities  A normal distribution curve can be used as a probability distribution.  Remember,
 A standardized value  A number of standard deviations a given value, x, is above or below the mean  z = (score (x) – mean)/s (standard deviation)
Normal Probability Distributions Chapter 5. § 5.2 Normal Distributions: Finding Probabilities.
Section 5.1 Introduction to Normal Distributions © 2012 Pearson Education, Inc. All rights reserved. 1 of 104.
Normal Probability Distributions 1 Larson/Farber 4th ed.
SWBAT: 5.2 -Calculate probabilities for normally distributed variables using a table or technology 5.3 -Calculate a z-score given the area under the curve.
Normal Probability Distributions Chapter 5. § 5.3 Normal Distributions: Finding Values.
Econ 110: Sampling Theory and Statistical Inference In Economics 2 nd semester 2016 richard makoto Economics Department University of Zimbabwe Normal Distribution.
Section 5.3 Normal Distributions: Finding Values © 2012 Pearson Education, Inc. All rights reserved. 1 of 104.
Chapter Normal Probability Distributions 1 of 25 5  2012 Pearson Education, Inc. All rights reserved.
Introduction to Normal Distributions
Chapter 7 The Normal Probability Distribution
Objectives Find probabilities for normally distributed variables
Finding Probability Using the Normal Curve
Chapter 5 Normal Probability Distributions.
5.2 Normal Distributions: Finding Probabilities
Finding Probabilities
Elementary Statistics: Picturing The World
Sections 5-1 and 5-2 Quiz Review Warm-Up
Chapter 5 Normal Probability Distributions.
Using the Normal Distribution
Normal Probability Distributions
Use the graph of the given normal distribution to identify μ and σ.
Sec Introduction to Normal Distributions
Normal Probability Distributions
Introduction to Normal Distributions
Chapter 5 Normal Probability Distributions.
Chapter 5 Normal Probability Distributions.
Chapter 5 Normal Probability Distributions.
Introduction to Normal Distributions
Normal Probability Distribution Lecture 1 Sections: 6.1 – 6.2
Presentation transcript:

The Standard Normal Distribution Section 5.2

The Standard Score The standard score, or z-score, represents the number of standard deviations a random variable x falls from the mean. The test scores for a civil service exam are normally distributed with a mean of 152 and a standard deviation of 7. Find the standard z-score for a person with a score of: (a) 161 (b) 148 (c) 152 (a)(b)(c)

The Standard Normal Distribution The standard normal distribution has a mean of 0 and a standard deviation of 1. Using z-scores any normal distribution can be transformed into the standard normal distribution. –4–3–2– z

Cumulative Areas The cumulative area is close to 1 for z-scores close to –1–2–3 z The total area under the curve is one. The cumulative area is close to 0 for z-scores close to –3.49. The cumulative area for z = 0 is

Find the cumulative area for a z-score of – –1–2–3 z Cumulative Areas Read down the z column on the left to z = –1.25 and across to the column under.05. The value in the cell is , the cumulative area. The probability that z is at most –1.25 is

Finding Probabilities To find the probability that z is less than a given value, read the cumulative area in the table corresponding to that z-score. 0123–1–2–3 z Read down the z-column to –1.4 and across to.05. The cumulative area is Find P(z < –1.45). P (z < –1.45) =

Finding Probabilities To find the probability that z is greater than a given value, subtract the cumulative area in the table from –1–2–3 z P(z > –1.24) = Find P(z > –1.24). The cumulative area (area to the left) is So the area to the right is 1 – =

Finding Probabilities To find the probability z is between two given values, find the cumulative areas for each and subtract the smaller area from the larger. Find P(–1.25 < z < 1.17). 1. P(z < 1.17) = P(z < –1.25) = P(–1.25 < z < 1.17) = – = –1–2–3 z

z Summary z To find the probability is greater than a given value, subtract the cumulative area in the table from z To find the probability z is between two given values, find the cumulative areas for each and subtract the smaller area from the larger. To find the probability that z is less than a given value, read the corresponding cumulative area.

Homework :1-15 all pgs Day 2: all pgs