Chap 1: Exploring Data 1.3: Measures of Center 1.4: Quartiles, Percentiles, and Box Plots 1.7: Variance and Standard Deviation
The Presentation of Data Dotplot (Dot-frequency diagram) Stemplot Stem: first digit or digits Leaf: last digit Frequency Table
Summation Notation
Suppose we wanted to sum the first 10 numbers: Let’s build a table:
Summation Notation
Using Summation Notation to Solve a Problem The corner section of a football stadium has 15 seats in the first row and 40 rows in all. Each successive row contains two additional seats. How many seats are in this section?
Using Summation Notation to Solve a Problem
Summation Notation
Mean
Median The middle value of a set of data Order the data from smallest to largest The median is the middle value When there exists an even number of elements, the median is the average of the two middle values Our previous data: 3, 3, 4, 6, 7 Median = 4
Mode The value that appears the most number of times in a set of data Our previous data: 3, 3, 4, 6, 7 Mode = 3
Measures of Center
Percentile The p th percentile of a set of numbers is a value in the set such that p percent of the numbers are less than or equal to that value. Max = 100 th percentile Min = 0 th percentile Median = 50 th percentile
Quartiles
Five Number Summary 1)Minimum 2)1 st Quartile = Lower Quartile 3)2 nd Quartile = Middle Quartile 4)3 rd Quartile = Upper Quartile 5)Maximum
Five Number Summary Calculate the average daily high temperature in Colorado Springs for June 2014 Generate a Five Number Summary for the daily high temperatures in Colorado Springs for June 2014 June 2014 Temperatures
June 2014 Temperatures
Box Plot Box-and-Whisker Plot A visual representation of a five-number summary 1)Draw a number line including the minimum and maximum data values 2)Draw a rectangle with opposite sides at the lower and upper quartiles of the data (hinges) 3)In the box, draw a segment parallel to the hinges at the median 4)Draw segments from the midpoints of the hinges to the min and max values (whiskers)
Box Plot Box-and-Whisker Plot
Outliers and the Interquartile Range
June 2014 Temperatures
Calculating the Variance and Standard Deviation
Variance and Standard Deviation
Example Problem (Test Scores)
Chap 1 Homework 1.3: Page 26#14 – : Pages 34 – 35 # 1 – : Page 58 # 1, 4, 5