Chapter 12 Statistics.

Slides:



Advertisements
Similar presentations
Chapter 2 Exploring Data with Graphs and Numerical Summaries
Advertisements

Unit 1.1 Investigating Data 1. Frequency and Histograms CCSS: S.ID.1 Represent data with plots on the real number line (dot plots, histograms, and box.
Chapter 13 Statistics © 2008 Pearson Addison-Wesley. All rights reserved.
12.3 – Measures of Dispersion
Warm-Up Exercises 1.Write the numbers in order from least to greatest. 82, 45, 98, 87, 82, The heights in inches of the basketball players in order.
Unit 3 Section 3-4.
Box and Whisker Plots and Quartiles Sixth Grade. Five Statistical Summary When describing a set of data we have seen that we can use measures such as.
381 Descriptive Statistics-III (Measures of Central Tendency) QSCI 381 – Lecture 5 (Larson and Farber, Sects 2.3 and 2.5)
12.4 – Measures of Position In some cases, the analysis of certain individual items in the data set is of more interest rather than the entire set. It.
0-12 Mean, Median, Mode, Range and Quartiles Objective: Calculate the measures of central tendency of a set of data.
SECTION 1-7: ANALYZING AND DISPLAYING DATA Goal: Use statistical measures and data displays to represent data.
Review Measures of central tendency
Chapter 6 1. Chebychev’s Theorem The portion of any data set lying within k standard deviations (k > 1) of the mean is at least: 2 k = 2: In any data.
Section 3.3 Measures of Relative Position HAWKES LEARNING SYSTEMS math courseware specialists Copyright © 2008 by Hawkes Learning Systems/Quant Systems,
Measure of Central Tendency Measures of central tendency – used to organize and summarize data so that you can understand a set of data. There are three.
Larson/Farber Ch 2 1 Elementary Statistics Larson Farber 2 Descriptive Statistics.
7.7 Statistics and Statistical Graphs. Learning Targets  Students should be able to… Use measures of central tendency and measures of dispersion to describe.
Chapter 2 Section 5 Notes Coach Bridges
Box and Whisker Plots Measures of Central Tendency.
Summary Statistics: Measures of Location and Dispersion.
Descriptive Statistics Chapter 2. § 2.5 Measures of Position.
Business Statistics, 4e, by Ken Black. © 2003 John Wiley & Sons. 3-1 Business Statistics, 4e by Ken Black Chapter 3 Descriptive Statistics.
Using Measures of Position (rather than value) to Describe Spread? 1.
Statistics topics from both Math 1 and Math 2, both featured on the GHSGT.
Larson/Farber Ch 2 1 Elementary Statistics Larson Farber 2 Descriptive Statistics.
MODULE 3: DESCRIPTIVE STATISTICS 2/6/2016BUS216: Probability & Statistics for Economics & Business 1.
Chapter 1 Lesson 4 Quartiles, Percentiles, and Box Plots.
Copyright © 2016 Brooks/Cole Cengage Learning Intro to Statistics Part II Descriptive Statistics Intro to Statistics Part II Descriptive Statistics Ernesto.
Chapter 3.3 – 3.4 Applications of the Standard Deviation and Measures of Relative Standing.
 2012 Pearson Education, Inc. Slide Chapter 12 Statistics.
Descriptive Statistics Chapter 2. § 2.5 Measures of Position.
Measures of Relative Standing and Boxplots
Measures of Position – Quartiles and Percentiles
Chapter 2 Descriptive Statistics.
Box and Whisker Plots.
Box and Whisker Plots and the 5 number summary
Box and Whisker Plots and the 5 number summary
Find the lower and upper quartiles for the data set.
Measures of Position Section 2-6
Intro to Statistics Part II Descriptive Statistics
Chapter 12 Statistics 2012 Pearson Education, Inc.
Measures of Position & Exploratory Data Analysis
Elementary Statistics
Intro to Statistics Part II Descriptive Statistics
Unit 2 Section 2.5.
Chapter 3 Describing Data Using Numerical Measures
10-3 Data Distributions Warm Up Lesson Presentation Lesson Quiz
Box and Whisker Plots Algebra 2.
A Modern View of the Data
Numerical Measures: Skewness and Location
Chapter 2 Descriptive Statistics.
Chapter 3 Section 4 Measures of Position.
Quartile Measures DCOVA
BOX-and-WHISKER PLOT (Box Plot)
Descriptive Statistics
Common Core State Standards:
12.4 – Measures of Position In some cases, the analysis of certain individual items in the data set is of more interest rather than the entire set. It.
Constructing Box Plots
Unit 12: Intro to Statistics
Box-And-Whisker Plots
1-4 Quartiles, Percentiles and Box Plots
MBA 510 Lecture 2 Spring 2013 Dr. Tonya Balan 4/20/2019.
Box-and-Whisker Plots
Box-And-Whisker Plots
Chapter 12 Statistics.
BOX-and-WHISKER PLOT (Box Plot)
Chapter 12 Statistics.
Ch. 12 Vocabulary 15.) quartile 16.) Interquartile range
Box Plot Lesson 11-4.
Presentation transcript:

Chapter 12 Statistics

Chapter 12: Statistics 12.1 Visual Displays of Data 12.2 Measures of Central Tendency 12.3 Measures of Dispersion 12.4 Measures of Position 12.5 The Normal Distribution

Section 12-4 Measures of Position

Measures of Position Understand the z-score. Compute and interpret percentiles. Compute and interpret deciles and quartiles. Work with box plots.

Measures of Position In some cases we are interested in certain individual items in the data set, rather than in the set as a whole. We need a way of measuring how an item fits into the collection, how it compares to other items in the collection, or even how it compares to another item in another collection. There are several common ways of creating such measures and they are usually called measures of position.

The z-Score If x is a data item in a sample with mean and standard deviation s, then the z-score of x is given by

Example: Comparing Positions Using z-Scores Two students, who take different history classes, had exams on the same day. Jen’s score was 83 while Joy’s score was 78. Which student did relatively better, given the class data shown below? Jen Joy Class mean 78 70 Class standard deviation 4 5

Example: Comparing Positions Using z-Scores Solution Calculate the z-scores: Since Joy’s z-score is higher, she was positioned relatively higher within her class than Jen was within her class.

Percentiles When you take a standardized test taken by larger numbers of students, your raw score is usually converted to a percentile score, which is defined on the next slide.

Percentiles If approximately n percent of the items in a distribution are less than the number x, then x is the nth percentile of the distribution, denoted Pn.

Example: Finding Percentiles The following are test scores (out of 100) for a particular math class. 44 56 58 62 64 64 70 72 72 72 74 74 75 78 78 79 80 82 82 84 86 87 88 90 92 95 96 96 98 100 Find the fortieth percentile.

Example: Finding Percentiles Solution The 40th percentile can be taken as the item below which 40 percent of the items are ranked. Since 40 percent of 30 is (0.40)(30) = 12, we take the thirteenth item, or 75, as the fortieth percentile.

Deciles and Quartiles Deciles are the nine values (denoted D1, D2,…, D9) along the scale that divide a data set into ten (approximately) equal parts, and quartiles are the three values (Q1, Q2, Q3) that divide the data set into four (approximately) equal parts.

Example: Finding Deciles The following are test scores (out of 100) for a particular math class. 44 56 58 62 64 64 70 72 72 72 74 74 75 78 78 79 80 82 82 84 86 87 88 90 92 95 96 96 98 100 Find the sixth decile.

Example: : Finding Deciles Solution The sixth decile is the 60th percentile. Since 60 percent of 30 is (0.60)(30) = 18, we take the nineteenth item, or 82, as the sixth decile.

Finding Quartiles For any set of data (ranked in order from least to greatest): The second quartile, Q2, is just the median. The first quartile, Q1, is the median of all items below Q2. The third quartile, Q3, is the median of all items above Q2.

Example: Finding Quartiles The following are test scores (out of 100) for a particular math class. 44 56 58 62 64 64 70 72 72 72 74 74 75 78 78 79 80 82 82 84 86 87 88 90 92 95 96 96 98 100 Find the three quartiles.

Example: Finding Quartiles Solution The two middle numbers are 78 and 79 so Q2 = (78 + 79)/2 = 78.5. There are 15 numbers above and 15 numbers below Q2. The middle number for the lower group is Q1 = 72. The middle number for the upper group is Q3 = 88.

The Box Plot A box plot, or box-and-whisker plot, involves the median (a measure of central tendency), the range (a measure of dispersion), and the first and third quartiles (measures of position), all incorporated into a simple visual display.

The Box Plot For a given set of data, a box plot (or box-and-whisker plot) consists of a rectangular box positioned above a numerical scale, extending from Q1 to Q3, with the value of Q2 (the median) indicated within the box, and with “whiskers” (line segments) extending to the left and right from the box out to the minimum and maximum data items.

Example: Constructing a Box Plot Construct a box plot for the weekly study times data shown below. 1 5 8 2 0 7 8 9 9 3 2 6 6 7 4 0 2 2 7 9 5 6 1 5 6

Example: Constructing a Box Plot Solution The minimum and maximum items are 15 and 66. 15 28.5 36.5 48 66 Q1 Q2 Q3