Lesson 2.92.1 · 2.3 · 2.9 Catch-Up
Start hereWords, worked example, and sentence starters
Learning target I can show I am caught up on Lessons 2.1 · 2.3 · 2.9 by using each lesson's big idea in mixed practice.
Why This Matters Missed a lesson — or just want a refresher? This catch-up station reviews Lessons 2.1 · 2.3 · 2.9: 2.1 Understand Statistical Questions, 2.3 Describe the Data Using the Median, 2.9 Describe Data by Mean Absolute Deviation. Work one example from each lesson, then prove you're caught up in the mixed practice.
Start hereWords for this lesson
Read each word before you begin. Say it out loud.
| Word | What it means | Example |
|---|---|---|
| Statistical QuestionSpanish: Pregunta estadística | A question where the answers will be different for different people. | “How tall are the players on the team?” → answers vary: 60 in, 63 in, 58 in, 65 in |
| Non-statistical QuestionSpanish: Pregunta no estadística | A question that does not anticipate variability in the data used to answer it. It may ask for one fact or measurement. | “How tall am I?” → one answer: 60 in. Everyone who measures gets the same number. |
| DataSpanish: Datos | Facts and numbers you collect, like answers to a survey. | Player heights: 60 in, 63 in, 58 in, 65 in — four different measurements |
| VariabilitySpanish: Variabilidad | How spread out the numbers are. | Scores 10, 12, 11 are close together (low variability); scores 2, 15, 30 are far apart (high variability) |
| SurveySpanish: Encuesta | Collecting facts by asking people questions. | Asking 50 students 'What is your favorite sport?' and recording the answers |
| Data distributionSpanish: Distribución de datos | How the data looks: where it sits and how spread out it is. | A distribution is symmetric when its left and right sides have approximately matching shapes around the center. |
How it worksWorked example
These numbers are not on your problems. The steps are. Follow them with your own numbers.
Four plants grew 3, 7, 8 and 10 cm. Find the MAD.
- Mean: 28 ÷ 4 = 7.
- Distances from 7: 4, 0, 1, 3.
- Sum = 8, and 8 ÷ 4 = 2.
Answer: MAD = 2 cm
Now you trySame steps, your turn
The steps are the same as the worked example. The numbers are yours. Do the work.
Is this a statistical question? "How many legs does a spider have?" Type yes or no.
Say it and write itSentence starters
Finish each sentence out loud with a partner. Then use them in your writing.
- The mean of this set is .
- The distance from to the mean is .
- The distances total , and there are values.
- The MAD is , which means .
Word bank mean absolute deviationdeviationdistanceabsolute valuemeanspreadaveragetotaldividetypicalconsistentvariation
Watch out!A common mistake
A common mistake in Mean Absolute Deviation is adding the signed deviations (value − mean) instead of their absolute values, so the positives and negatives cancel out to 0. For 6, 8, 10, 12 (mean = 9), the deviations are −3, −1, 1, 3
Lesson 2.92.1 · 2.3 · 2.9 Catch-Up
Catch-UpSkill bridge
Learning target I can show I am caught up on Lessons 2.1 · 2.3 · 2.9 by using each lesson's big idea in mixed practice.
Why This Matters Missed a lesson — or just want a refresher? This catch-up station reviews Lessons 2.1 · 2.3 · 2.9: 2.1 Understand Statistical Questions, 2.3 Describe the Data Using the Median, 2.9 Describe Data by Mean Absolute Deviation. Work one example from each lesson, then prove you're caught up in the mixed practice.
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1Complete each step, then write the final answer.
Is this a statistical question? "What is each student's favorite fruit?" Type yes or no.
Show your workHint Will every student say the same fruit?
Final answer: -
2Complete each step, then write the final answer.
Is this a statistical question? "How many wheels does a bike have?" Type yes or no.
Show your workHint How many different answers can this question have?
Final answer: -
3Complete each step, then write the final answer.
Find the median of this data set: 4, 1, 7, 3, 9.
Show your workHint Put the values in order first.
Final answer: -
4Complete each step, then write the final answer.
Find the median of this data set: 10, 2, 8, 6.
Show your workHint Four values have two middle values.
Final answer: -
5Complete each step, then write the final answer.
Find the MAD of this data set: 1, 4, 7.
Show your workHint The mean is 4. Find how far 1, 4 and 7 are from 4.
Final answer: -
6Complete each step, then write the final answer.
Find the MAD of this data set: 5, 6, 10, 11.
Show your workHint The values add to 32. Find the mean, then each distance from it.
Final answer:
Explain your thinkingPlayer A's MAD is 2.4 points. If Player B's MAD is 7.2 points, what does that tell you about their consistency?
Sentence starter Player A has a ___ MAD, which means their scores are ___ to the mean. Player B has a ___ MAD, which means their scores are ___ from the mean. The more consistent player is ___ because ___.