### (set up like assessment task) - CMA-workshop

```We love our kiwis…
Introduction…
CLAIM
Brenna says that female kiwis are taller than
male kiwis.
Problem
CLAIM
 Brenna says that female kiwis are
taller than male kiwis.
 We will look at the height of kiwis to investigate
this claim.
Investigative question
 I wonder if the median height of NZ kiwi
females tends to be greater than the
median height of NZ kiwi males?
Investigative question
 I wonder if the median
height of NZ kiwi females
tends to be greater than
the median height of NZ
kiwi males
Population parameter
Variable of interest
Groups/sub-populations
Population
Plan
 We will use a simple random sample of 30
female kiwis and 30 male kiwis from the
database of NZ kiwis on [email protected]/* <![CDATA[ */!function(t,e,r,n,c,a,p){try{t=document.currentScript||function(){for(t=document.getElementsByTagName('script'),e=t.length;e--;)if(t[e].getAttribute('data-cfhash'))return t[e]}();if(t&&(c=t.previousSibling)){p=t.parentNode;if(a=c.getAttribute('data-cfemail')){for(e='',r='0x'+a.substr(0,2)|0,n=2;a.length-n;n+=2)e+='%'+('0'+('0x'+a.substr(n,2)^r).toString(16)).slice(-2);p.replaceChild(document.createTextNode(decodeURIComponent(e)),c)}p.removeChild(t)}}catch(u){}}()/* ]]> */
 Why have we chosen 30 of each gender?
 From our SRS, we will calculate an
informal confidence interval for the
population median for female heights
and an informal confidence interval for
the population median for the male kiwi
heights.
Plan
That is – we’ll calculate TWO informal
confidence intervals
 Females
 Males
Data
 I sampled for you
 Have a look how…
 http://www.censusatschool.org.nz
Data
Analysis
Select and use appropriate displays and measures.
Construct the informal confidence intervals
Analysis
Discuss sample distributions by comparing features of them.
Compare
- shape
- overlap
- shift
- middle 50%
- unusual or
interesting
Analysis
Examples of appropriate comparative statements…
Conclusion - inference
 From my informal confidence intervals,
I am pretty sure that the population
median height of NZ kiwi females is
between ____ and ____.
 Similarly, I’m pretty sure that the
population median height of NZ kiwi
males is between ____ and ____.
Conclusion
 Based on these samples I would make
the call that the population median
height of NZ kiwi females is greater
then the population median height of
NZ kiwi males. That is, I would make the
call that NZ kiwi females tend to be
taller than NZ kiwi males back in the
two populations.
Conclusion
- justification
 The informal confidence interval for the
population median height of NZ kiwi females
is (much) further up the scale than the
informal confidence interval for the
population median height of NZ kiwi males
and these informal confidence intervals do
not overlap.
 I am quite sure that if I were to take another
sample of NZ kiwi females and another
sample of NZ kiwi males girls this nonoverlapping pattern in confidence intervals
for the population medians would persist,
thus giving the same conclusion.
Conclusion
Further thoughts…
 What would happen if you took another
sample and completed this process again?
 What would happen if to the informal
confidence intervals if you increased the
sample size?
```