Mean, Median, Mode, Range / HW: #14.1
Friday 3/20 / Lesson14.2
Statistical Measures / HW #14.2
IXL: AA.1 due Tues 3/24
Monday 3/23 / Lesson 14.3
Inferences about Populations / HW # 14.3
Tuesday 3/24 / Lesson 14.4
Measures of Center / HW #14.4
Wednesday 3/25 / Lesson 14.5
Measures of Variability / HW #14.5
Thursday 3/26 / Lesson 14.6
Mean Absolute Deviation / HW #14.6
IXL: AA.2 due Mon 3/30
Friday 3/27 / Lesson 14.7
Review / HW #14.7
Monday 3/30 / Review & TEST
Review- Percents & Fractions
Do Now Page
- When are averages used? Name at least 2 examples.
- During eruptions, a geyser’s water soars up to various heights. Find the mean
- Using the information below: determine the following:
Q1:
Median:
Q3:
Min:
Max:
Interquartile Range: /
- What inference can you make based on this data?
- Go to the Lesson 14.5 and start the first question.
- Go to Lesson 14.6 and start the first question
- If I buy snowboarding pants for $80.50, a new jacket for $154 and gloves for $15.50. If there is 8% tax added to my bill, how much will I owe for my new gear?
Lesson 14.1: Statistics Review: Mean, Median, Mode & Range
Data Set: 98 75 70 78 92 86 82 86
Mean:aka “Average”- Find the sum of the numbers, then divide by the number of values.
Median:aka “the middle”- After putting the numbers in order, cross out values one at a time from the front and back to find the middle. *If there are 2 numbers in the middle, find the mean of those 2 numbers.
Mode: aka “the most” Is there a value that appears the most?
Range:Subtract the smallest value from the largest value.
Data Practice:
Mean: Add up all values. Then divide by how many numbers you have.Median: Put all numbers in order from least to greatest. Cross out until you find the middle number. (If 2 middle numbers, find the mean of those two)
Mode: Find any number that repeats more often than other others.
Range: Subtract the smallest value from the largest value.
Lesson 14.2: Statistical Measures
Quartiles:The quartiles of a data set, divide the data into four parts with the same number of data values in each part.
Interquartile Range (IQR):
The IQR is the difference between the first and third quartiles of the data set. It represents the spread of the middle 50% of the data.
Example: You are visiting different hot springs in Yellowstone. A box plot is made from the temperatures you record.
- Find the range and the interquartile range
of the temperatures.
- Describe the variability of temperature in the hot springs.
Exploring Activity:
Goals: To explore quartiles, and create box plots
You are visiting different hot springs in Yellowstone. Here are the depths of the hot spring pools you record.
Depths of Hot Springs (feet) 25, 6, 27, 26, 23.5, 25, 32.5
Notes:
Summary:
Use the numbers below to draw a box plot
7, 7, 8, 8, 8, 9, 9, 9, 10, 12, 12, 12
Minimum:
Maximum:
Range:
Median:
First Quartile:
Third Quartile:
Interquartile Range:
Lesson 14.3: Inferences on Populations
/ One PopulationUse one population when you have a question about the whole group.
/ Two Populations
Use two populations when you want to compare two groups or two parts of a group.
/ Multiple Populations
Use the number of populations needed to answer the question you have.
A teacher gave a test to each of her 3 math classes. Determine how to organize the population, into one group, two groups, or multiple groups?
What was the highest score overall? / Who did better boys or girls? / Which is the top scoring class? / What is the mean score in each class?Inference: When you make a judgment by interpreting a set of data, you are making an inference.
Example:
Write a sentence comparing Class A & Class B. What is an inference you can make?
______
______
______
Practice:
- The school nurse tested the eyesight of all the students in Grade 6, 7, and 8. To answer each question, should the nurse consider the grades as three populations or one population?
How many students have perfect vision in the school? / What is the mean eyesight score for each grade? / Do students’ eyesight scores change more between 6th and 7th grades or between 7th and 8th grades?
- The following two dot plots show how many students attended home baseball games for two recent seasons.
What is an inference you can make about the data? How can you compare the two graphs?
______
______
______
- A researcher is analyzing US census data. For each question, how many population(s) should the researcher use? Describe the population(s).
Lesson 14.4: Measures of Center
Measures of center: Mean & Median
Mean or Median?
Data set: 4, 2, 6, 8, 1, 0Data set: 23, 25, 22, 29, 54, 30
Example: A biology student is studying two species of parrots. What is the median wingspan of each sample. What inference can you make based on these values?
Inference:______
Example:
Inference:______
Practice:
- A book publisher is testing two versions of a new book. A random sample of people are given 30 minutes to read each version. What is the median of each sample. What inference can you make based on this data?
Inference:______
- Based on the information provided, which measure of center would you use for each set of data? Explain.
Inference: ______
Inference: ____________
______
______/ Inference: ______
______
______
______
Lesson 14.5: Measures of Variability
Example 1: A researcher is studying the effects of owning a cell phone on the number of hours people sleep. What is the range of hours slept for each group? Make a comparative inference about the populations based on range.
Example 2: A psychologist is studying how spending time outdoors affects people’s moods. He surveys two samples of people chosen at random. What is the interquartile range of mood levels for each sample? Make a comparative inference about the population based on the IQR.
Practice:
Find the median and IQR of both sets of data.
Find the median and IQR for each box plot:
Lesson 14.6: Mean Absolute Deviation
Calculate the mean and range of the heights of each group of athletes. What inferences can you make?
Mean Absolute Deviation:
Steps:- Find the MEAN
- Find the Deviations
- Absolute Deviation
- MEAN
Summary Sentence: ______is the average distance the values are from the mean.
Steps:
1)Find the mean / 2)Find the deviations (Subtract each original data value from the mean) / 3)Find the absolute deviation of each answer / 4)Find the mean of those answers.Lesson 14.7: Review
Study Guide: Statistics
Question / Correct Answer / Your Score- How do you calculate the mean?
- Define mode.
- Use the following information:
What is the median? / 1)Put the numbers in order from least to greatest
56, 69, 71, 79, 85, 87, 91
Cross out numbers, until you get to the middle, Median = 79 / 2 1 0
- What does Mean absolute deviation mean?
- Based on
Identify the following:
Q1, Q3, Median, Max, Min, Range, IQR / Min: 9
Q1: 11.5
Median 20.5
Q3: 25.5
Max: 30
Range: 30-9 = 21
IQR 25.5 – 11.5 = 14 / 2 1 0
- If Mr. Z wanted to study the grades of students in math and answer the question “The students in which grade have the highest test grades?
Practice Questions:
Mean absolute deviation:
Reading box plot
Interpreting data:
What inference(s) can you make about the attendance in 2009 and 2010? Use a measure of center to explain.
______
______
______
On your test:
Mean, Median, Mode, Range
Reading a box plot: Min, Q1, median, Q3, maximum, IQR
Finding the Mean Absolute Deviation
Determining how many populations are needed
Comparing two populations using measure of center to make an inference.
*Fractions & Percents!