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Friday, April 11, 2014 [Day C]. Exploratory Exploratory Math English/ LUNCH /English Locker Time Science Social Studies. Friday, April 11, 2014 [Day C]. Activator : Pass in your H.W. Pick up a “Minute Journal” on top of projector. Grade 6 Math – ANet 4. Grade 6 Math – ANet 4.
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Friday, April 11, 2014 [Day C] Exploratory Exploratory Math English/LUNCH/English Locker Time Science Social Studies
Friday, April 11, 2014 [Day C] Activator: Pass in your H.W. Pick up a “Minute Journal” on top of projector
Unit # 4: Statistics 6th grade Statistics is the study of how to collect, organize, analyze, and interpret data
“We are rapidly entering a world where everything can be monitored and measured but the big problem is going to be the ability of humans to use, analyze, and make sense of the data.” • The New York Times • August 6, 2009
Essential Questions • 1. How do we properly collect data? • 2. How do we organize data? • 3. How do we analyze data? • 4. How do we interpret results?
To properly collect data, we must first ask a question that will result in multiple and varying answers rather than a single answer. A statistical question will result in variability in data and involve a real-world context.
Sort the following questions into two groups: statistical & non-statistical • 1. How old is the oldest student in our class? • 2. Are there more boys or girls in our class? • 3. How old are the students in our class? • 4. How long do students in this class spend on math homework each week? • 5. How many students in our class like to watch scary movies? • 6. What types of movies are preferred by students in our class?
Statistical or Non-Statistical Statistical • 3. How old are the students in our class? • 4. How long do students in this class spend on math homework each week? • 6. What types of movies are preferred by students in our class? Non-Statistical • 1. How old is the oldest student in our class? • 2. Are there more boys or girls in our class? • 5. How many students in our class like to watch scary movies?
Pick one of the following topics 1. TV habits 2. Cell phone usage 3. Eating fruits and vegetables 4. Watching sports Write a statistical question and a non-statistical question about your topic.
A statistical question is a question that will result in multiple and varying answers rather than a single answer. • Statistical questions can be divided into two groups: categorical or numerical.
Categorical data • Categorical data is measured qualitatively by placing the items into categories or groups. Ex. Favorite color, male or female, hair color • Categorical data is often displayed using a bar graph or a circle graph
Categorical data • Often times, categorical data does not involve numbers, therefore will not have a mean, median, or range. The mode is the answer that occurs most often. The mode is the most useful calculation for categorical data.
Numerical Data • Numerical data is measured quantitatively and has a value or number for which operations such as addition or averaging make sense. Numerical data can be analyzed to find mean, median, range, and other forms of measurement Numerical data is often displayed using a line plot (dot plot), histogram, or box and whisker plot. *We will study each of these in more detail throughout this unit
Sort the questions from your envelope into two groups: Get into groups of 3 Categorical Numerical http://grade6commoncoremath.wikispaces.hcpss.org/Unit+5+Statistics+Probability 6.SP.1 Categorical and Numerical Questions
Identify whether the following graphs are categorical or numerical
Activity: • In five days, it snowed 4 inches, 3 inches, 5 inches, 1 inch, and 2 inches. 4 in 3 in 5 in 1 in 2 in • Move the cubes until each stack has the same number of cubes. Oklahoma Math Connects Course 1 – Glencoe 2011 – pg. 102
Activity Summary: • 1. On average, how many inches did it snow per day in five days? Explain your reasoning. • 2. Suppose on the sixth day it snowed 9 inches. If you moved the cubes again, how many cubes would be in each stack. Oklahoma Math Connects Course 1 – Glencoe 2011 – pg. 102
Mean (or average) – the results from equally distributing all the data in a set. The mean can be found in either of the following ways • The mean can be found by leveling all the values to have an equal distribution. • http://www.shodor.org/interactivate/activities/PlopIt/ • The mean is the sum of the data divided by the number of pieces of data. • Ex. Data set: 4, 3, 2, 5, 1 • Mean: 4 + 3 + 2 + 5 + 1 5 = 15/5 Mean = 3
Find the mean of the data sets below. • Years of experience on a baseball team • Cell phone usage 478 295 780 685 570 588 495 390 587 376 4 6 3 2 1 0 6 4 5 3 2
Outliers • Outliers are values that are much higher or lower than others in a data set Chapter 5 Test Scores 1. Calculate the mean of the data set. 2. Calculate the mean leaving out the score of 0. 3. Calculate the mean leaving out both the 20 and the 0. 100 99 98 96 95 88 86 81 79 76 66 64 52 20 0 Answers: 1. 73.3, 2. 78.6, 3. 83.1
Identify the outlier(s) in these costs: • $115, $125, $55, $135, $400, $105, $115, $140 • Calculate the mean of the data set. • Calculate the mean of the data set without the outlier(s). Answers: The outliers would be $400 and $55. The mean of the entire data set is $148.75. The mean without the outliers is $122.50.
Write at least three sentences describing how outliers can distort calculations of the mean.
Bell work Allison’s Math Test Scores The table shows Allison’s scores on four tests. What score does she need on the 5th test to have an overall mean score of 92?
One possible solution strategy 1. Add up the points for the first 4 test scores. 89 + 98 + 85 + 94 = 366 • Find out how many points it would take to get a 92 average. 92 x 5 = 460 • Subtract to find the points needed on the 5th test. 460-366 = 94
Analyzing Numerical Data • A set of data collected to answer a statistical question has a distribution which can be described by its center, spread, and overall shape. • CENTER - A measure of center summarizes all of the values of a data set with a single number (mean, median, mode) • SPREAD - Describes how spread out or varied the data is (range) • OVERALL SHAPE – Skewed left, skewed right, normal distribution, uniform distribution, bimodal distribution
Measures of Center • Mean – also called the average, fair share or balance point of a set of data – it can be found using a leveling strategy or by finding the sum of the data divided by the number of pieces of data. • Median – the middle number in a set of data ordered from smallest to largest. If the data set has an odd number of elements, the median is the single middle value. If the data set has an even number of elements, the median is the average of the two middle values. • Mode – the number(s) that occur(s) most often (there can be more than one mode in a data set)
Measures of Spread or Variability • Range – the difference between the greatest and least values of the set • Mean Absolute Deviation- the absolute value of each data point from the mean of the data set
Hey diddle diddle The median’s in the middle; You add and divide for the mean. The mode is the one that appears the most And the range is the difference between.
Points scored by a basketball team Find the mean number of points scored. Find the median number of points scored. What do the values of the mean and median tell you about the overall shape or distribution of the data?
Puzzle Times • Each of the 20 students in Mr. Anderson’s class timed how long it took them to solve a puzzle. Their times (in minutes) are listed below: • Display the data using a line plot. • Find the mean and median of the data. Does it surprise you that the values of the mean and median are not equal? Explain why or why not. http://www.illustrativemathematics.org/illustrations/877
Overall Shape Bimodal Distribution Normal Distribution Uniform Distribution Skewed Right Skewed Left
Day 5 • 2nd day on previous material • Also, we need to address when finding the mean is the best strategy, when finding the median is best, and when finding the mode is best.
This measure is most useful when: • Mean – the data have no outliers (values much larger or smaller than the rest of the data) • Median – the data contains outliers • Mode – data have many repeated numbers or the data is categorical in nature
1. Jamal said that the number that best represented the following set of data is 27. Which measure of central tendency is he referring to? 28, 32, 21, 25, 33, 32, 20, 26 • 2. The number of books read by the students in each core literacy class is: 104, 90, 162, 134, 110, 97, 145, 126. Which measure of central tendency best describes the data? Explain. Glencoe Pre-Algebra (2012) pg. 779
3. The high temperatures for one week are 79°, 81°, 77°, 81°, 82°, 75°, and 76°. If the temperature on the eighth day is 80°, which of the following would be true? A. The mode will change B. The mean will increase and the median will remain the same C. The median will increase and the mean will remain the same D. Both the mean and the median will increase Glencoe Pre-Algebra (2012) pg. 779
Bell work: *ACT Aspire Sample Question • Nigel’s class placed 10 empty rain gauges on the playground Monday morning. The line plot below shows the number of inches of rainwater in each gauge after it rained Monday afternoon. Number of Inches of Rainwater x x x xx x xxxx 3/8 1/2 5/8 3/4 7/8 What is the mean amount of rainwater per gauge, in inches, in the 10 rain gauges?
What is the mean amount of rainwater per gauge, in inches, in the 10 rain gauges? A. 25/80 B. 5/8 C. 51/80 D. 37/56 E. 51/8 Answer: C
Mean absolute deviation • Measures the average amount that the items of a data set differ from the mean of the set. • Find the mean • Find the difference of each value from the mean • Subtract the smaller value from the larger value, so each difference is positive • Find the mean absolute deviation by averaging the differences
Hours worked on a Saturday: 4, 5, 7, 12 • Mean = (4 + 5 + 7 + 12)/ 4 = 7 • Deviations from the mean = 3, 2 , 0, 5 • Mean absolute deviation = (3 + 2 + 0 + 5)/4 = 10/4 = 2.5