Honors Stats

Objectives:SWBT:

Identify the context of data, or realize that some parts of the context are not provided.

Identify the variables in a data set, and classify which type each one is.

Classroom SurveyWhere you surprised by anything?

Struggled with anything?

How did you choose to represent the data?

Classroom SurveyBedtime

Time you fell asleep or time you got into bed or time you turned off the lights?

Shoe SizeMen’s 7 and Women’s 7 are VERY different. What if

someone was from the UK?

What is Data?Systematically recorded information, whether

numbers or labels, together with its context.

Why does the context matter?

Context Matters12, 15, 20, 30, 72

Context Matters12, 15, 20, 30, 72

If it’s scores on a test we feel differently than if it’s the numbers on five people’s football jerseys.

Context5 Ws+H.

Who was measuredWhat was measuredHow the data was collectedWhere the data was collectedWhen/Why the study was performed

When given data, look for these 5Ws!

Example OneA Consumer Reports article on energy bars gave

the brand name, flavor, price, number of calories, and grams of protein and fat.

Give the context

5WsWho?

What?

How?

Where?

When?

Why?

5WsWho? Energy Bars

What? Brand Name, Flavor, Price, Calories, Protein, Fat

How? Not specified… hmmm. Is data collected from companies? From labels?

Where? Not specified

When? Not specified.

Why? To inform potential consumers.

Problems: Example One1. Not enough information is given! We have no

where or when or how!

2. Bigger Problem? UNITS! What units was the price? Was it dollars, pounds, euro?

UNITSThings need to be measured with the same

units! Ex:

Hard to compare male/female shoe sizes because they are different!

Is price considered in American dollars, pounds, euro?

Bedtime– what is considered bedtime? In order to have data that makes sense you need

to specify the UNITS.

Context Lacking Quotes from your graphs handed in on Friday:

“From this graph it is obvious that most students don’t carry money on them.”

“The latest bedtime was 3 am and the average bedtime was 11 pm.”

“(This is a) T-Chart graphing all the students on the left, and whether they have eaten sushi or not.”

Context Lacking (continued)

The most common time for high school students to go to bed is 11 pm.

Everyone estimated that Mr. Delery was in his high 20s, low 30s.

Most people go to bed around 11:00, and nobody went to bed before 10:00.

Lesson?When giving a context- be specific :D

VariablesDefinition: The characteristics recorded about

each individual case.

Note: In stats certain terms you have seen in math will be defined differently! Stats has its own vocabulary!

Two Types of VariablesCategorical

Variables that names categories (whether with words or numerals)

Ex: Grade, Country of origin

2 Types of Variables:Quantitative

Variables in which the numbers act as numerical values.

Quantitative variables must have a UNIT.

Ex: Height, age, distance

Example One RevisitedA Consumer Reports article on energy bars gave

the brand name, flavor, price, number of calories, and grams of protein and fat.

What are the variables? Which type are they?

Example One: VariablesCategorical Variables: Brand Name, Flavor

Quantitative Variables: Price (US $$), number of calories (calories), protein (grams), fat (grams)

Types can be Tricky….What type a variable is can often be rather easy

to figure out.YET. Notice that the type mostly depends on how

we display and analyze the dataEx: Age

If we use actual age it is quantitativeIf we just use basic categories like child, adult, senior

then it is categorical.

Example Two: A report on the Boston Marathon listed each

runner’s gender, country of origin, age and time.

Context? Variables?

Example Two: Who?

What?

When?

Where?

Why?

Example Two: Who? Boston Marathon Runners

What? Gender, Country, Age, Time

When? Not specified

Where? Boston, MA

Why? Race result reporting

How? Unknown….

Example Two: Variables

Categorical:

Quantitative:

Example Two: Variables

Categorical: gender, country of origin

Quantitative: age (years), time (hours, minutes, seconds)

PracticeTry some on your own or in your groups– at least

check your answers with your group members.

Exit Ticket A study was conducted to compare the abilities

of men and women to preform strenuous tasks required of a shipboard firefighter. The student reports the pulling force (in Newtons) that a firefighter was able to exert in pulling the starter cord of a P-250 water pump. The study also gives the weight and gender of the firefighters.

Give context/identify variables.