- A sixth form college has 84 students in Year 12 and 56 students in Year 13
The head teacher selects a stratified sample of 40 students, stratified by year group.
- Describe how this sample could be taken.
The head teacher is investigating the relationship between the amount of sleep, s hours, that each student had the night before they took an aptitude test and their performance in the test, \(p\) marks.
For the sample of 40 students, he finds the equation of the regression line of \(p\) on \(s\) to be
$$p = 26.1 + 5.60 s$$ - With reference to this equation, describe the effect that an extra 0.5 hours of sleep may have, on average, on a student's performance in the aptitude test.
- Describe one limitation of this regression model.