Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Sections 2.3 and 2.4 Quiz 2.3 – 2.4 tomorrow (or next school day) -May use 1 side of a 4 x 6 note card for the quiz Percentiles and Cumulative Relative Frequency Plots Percentiles measure position within a data set. Percentiles and Cumulative Relative Frequency Plots Percentiles measure position within a data set. Q1 is 25th percentile - - the value that separates the lowest 25% of the ordered values from the rest Median is ______ percentile Percentiles and Cumulative Relative Frequency Plots Percentiles measure position within a data set. Q1 is 25th percentile - - the value that separates the lowest 25% of the ordered values from the rest Median is 50th percentile Q3 is the _____ percentile Percentiles and Cumulative Relative Frequency Plots Percentiles measure position within a data set. Q1 is 25th percentile - - the value that separates the lowest 25% of the ordered values from the rest Median is 50th percentile Q3 is the 75th percentile Percentiles and Cumulative Relative Frequency Plots In general, a value is at the kth percentile if k% of all values are less than or equal to it. Suppose you have a set of univariate data (data that involves a single variable per case). The data consists of the weights of the students in a class. What are the cases? What is the variable? Suppose you have a set of univariate data (data that involves a single variable per case). The data consists of the weights of the students in a class. What are the cases? Individual students What is the variable? Suppose you have a set of univariate data (data that involves a single variable per case). The data consists of the weights of the students in a class. What are the cases? Individual students What is the variable? The weight for each student The data consists of the weights of the students in a class. List all the measures you know to describe the data set. Hint: Should list 11 measures List all the measures you know to describe the data set. x, sx, median, Q1, Q3, min, max, range, IQR, mode, and outliers List all the measures you know to describe the data set. x, sx, median, Q1, Q3, min, max, range, IQR, mode, and outliers Now categorize these measures in terms of describing shape, center, or spread. List all the measures you know to describe the data set. x, sx, median, Q1, Q3, min, max, range, IQR, mode, and outliers Now categorize these measures in terms of describing shape, center, or spread. None of these alone describe the shape. How do you describe the shape? How do you describe the shape? • • • • uniform normal distribution skewed left or right bimodal Page 80, P28 P28 (Rescaling) (a) converting height from inches to feet is rescaling Which measures are affected by rescaling? P28 (Rescaling) (a) converting height from inches to feet is rescaling Which measures are affected by rescaling? • mean • median • standard deviation • and IQR P28 (Rescaling) (a) Divide each of the summary statistics by 12 so: • the mean is P28 (Rescaling) (a) Divide each of the summary statistics by 12 so: • the mean is 4 feet • the standard deviation is P28 (Rescaling) (a) Divide each of the summary statistics by 12 so: • the mean is 4 feet • the standard deviation is 0.2 foot • the median is P28 (Rescaling) (a) Divide each of the summary statistics by 12 so: • the mean is 4 feet • the standard deviation is 0.2 foot • the median is 3.75 feet and • the IQR is P28 (Rescaling) (a) Divide each of the summary statistics by 12 so: • the mean is 4 feet • the standard deviation is 0.2 foot • the median is 3.75 feet and • the IQR is 0.25 foot P28 (b) each child growing 2 inches is ____________ P28 (Recentering) (b) each child growing 2 inches is recentering P28 (Recentering) (b) each child growing 2 inches is recentering Which measures are affected by recentering? P28 (Recentering) (b) each child growing 2 inches is recentering Which measures are affected by recentering? Only the centers: • mean • median P28 (Recentering) (b) Add 2 to the measures of the center so • mean is 50 inches • median is 47 inches Recentering does not change the spread so • standard deviation stays 2.4 inches • IQR stays 3 inches P28 (Recentering and Rescaling) (c) each child growing 4 inches is recentering and converting heights to feet is rescaling. P28 (Recentering and Rescaling) (c) P28 (Recentering and Rescaling) (c) Plot this data into a stem-and-leaf plot: 23, 125, 8, 23, 50 Plot this data into a stem-and-leaf plot: 23, 125, 8, 23, 50 0 2 5 12 8 3 3 0 5 Plot this data into a stem-and-leaf plot: 23, 125, 8, 23, 50 0 2 5 12 8 3 3 0 5 5 0 represents 50 Page 69, P15 P15 The new mean height will be about 4 feet 4 inches. x = [5(4) + 6]÷ 6 P15 The new mean height will be about 4 feet 4 inches. The median will not change because it will still be one of the heights of the 3rd graders, who all are about 4 feet tall. 4 4 4 4 4 6 Page 70, P21 Use calculator to find (a) 5-number summary and (e) to draw a modified boxplot. Also answer (b), (c), and (d), P21 P21 P21 Page 72, E33 • Enter Predator data in List 1 • Enter NonPredator data in List 2 Page 72, E33 • Enter Predator data in List 1 • Enter NonPredator data in List 2 • Use L1 for Plot 1 and L2 for Plot 2 to display both modified boxplots on same screen E33 Page 73, E43 Page 73, E43 Enter Weights in List 1 Enter Frequency in List 2 E43 Page 81, E53 Page 81, E53 a. Median: 23 or 24 cents. To estimate this, find the amount of change that corresponds to the 50th percentile Page 81, E53 a. Median: 23 or 24 cents. To estimate this, find the amount of change that corresponds to the 50th percentile b. Q1 ≈ 10 cents and Q3 ≈ 70 cents. Q1 corresponds to 25th percentile and Q3 corresponds to 25th percentile IQR = 60 cents E53 Page 82, E54 E54 Page 82, E57 E57 Questions?