Inference and box plots

114 Views

Download Presentation
## Inference and box plots

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -

**Lesson 4**Inference and box plots**Focus**• Inferring back to the population • Box plots**PROBLEM**• Do boys at Karekare College tend to have longer popliteal lengths than girls at Karekare college?**DATA**• Sample of 30ish boys and 30ish girls from Karakare College**ANALYSIS**• I notice… • Write three I notice statements about this graph…**ANALYSIS**• I notice… (describe what is happening in your samples) • I wonder… (inferential statement about what might be happening back in your population)**Box plot reminder**MEDIAN – halfway through ordered data • Mark the middle of all the values… • How do we find this? • Odd/even sample sizes? • What is the name of this STATISTIC?**QUARTILES–quarter of the way through ordered data**Box plot reminder • Mark the middle of the bottom half and the middle of the top half… • How do we find this? • Median included or not? • What is the name of these STATISTICS?**Box plot reminder**• Join these three values up with a box • The middle value is a line through the box • Extend a line from the box to the smallest and largest values • Congratulations – you’ve made a box plot!**Box plot reminder**• Box plots split the data up into quarters • We often refer to the middle 50% which is the box part.