Statistics 1
Agenda for Thursday, December 6

·  Extra help is available! You can find me after school in Room 202. I will be there today until 4. If you are intimidated by the whole portfolio submission thing, you should come talk to me.

·  Get out your homework sheet, Random Homework. Put it in the folder to be submitted. We will be discussing it in small groups tomorrow. (New groups start tomorrow.)

·  From the folder, take the sheet Histogram Portfolio Submission. We will have a small group discussion about the instruction sheet for the portfolio to be sure everybody knows what to do.


You will be starting the portfolio work tonight and finishing it for Monday. You cannot use a coupon for portfolio work.


Small Group Portfolio Discussion—10 Minutes

Presider: Spades

Recorder: Diamonds

Quality Control Specialist: Hearts

Presenter: Clubs

The questions are:

Say something about rules for histograms (each person say something different) / Identify anything confusing or tricky about the data table / What did we say yesterday about computing the median? How would we get started on that?

Whole Class Portfolio Discussion– 10 Minutes

Summarize the Rules for Histograms

·  Bin width must be equal.

·  Quantitative variable goes on the x axis

·  No spaces between the bins

·  The y axis needs to start at zero

·  Frequency goes on the y axis

·  Used for one quantitative variable

·  Be careful about the bin edges. You can’t have the same value included in more than one bin.

Clarify any remaining questions about what to do for portfolio


Misleading Graphs (continue from yesterday’s discussion)

Some things we observed about graphs in general:

·  y axis must start at zero

·  must use consistent scale on an axis

·  labeling matters. What are you actually measuring?

http://freethoughtblogs.com/lousycanuck/2011/12/14/im-better-at-graphs-than-fox-news/

http://www.theatlantic.com/business/archive/2012/06/hey-everyone-dont-fall-for-this-misleading-graph-about-college-costs/258299/

·  If you are showing the trend of more than one thing on the same graph, make sure both things are measured with the same units. (eg dollars/year, or # of days, etc.)

Individual Activity—15 minutes


Statistics 1
Fake Quiz—just a class participation grade, not a test score

1) Suppose your family will be moving to a new town and you want to get a sense of housing prices in that area. When you contact a real estate agent, would you ask for the median price of a house or the mean price of a house? Explain your choice.

2) Draw a sketch of a distribution where the mean would be significantly less than the median. Say how you know from the shape of the distribution that the mean is below than the median.

On the bottom of the sheet (or the back) rate your confidence in answering these questions.