Report

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] 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 - spread - 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?