Vocabulary
What's Wrong
Z-score
Distributions
Correlations + Regressions
100
Extrapolation definition
What is the use of a regression line for prediction far outside the range of values of the explanatory variable used to obtain the line
100
WHAT IS WRONG WITH THIS?
Ron runs a correlation to see if there is a possible relationship between food consumed and hours of sleep. He calculates a correlation coefficient of r=1.32 and concludes that there is a strong and positive relationship between the two.
-1<r<1, therefore the coefficient calculated is impossible
100
Hermione scores in the 95th percentile of her class, therefore her z-score would be...
What is z=1.65
100
Percentage of data between the minimum and 3rd quartile
What is 75%
100
Draw a graph that has a correlation coefficient of 0
200
May explain or influence changes in a response variable (independent variable)
What is an explanatory variable
200
Hagrid's shoe size is 18 while the male shoe size at Hogwarts is normally distributed with a mean of 11.3 and a standard deviation of 2.3. Hagrid calculates his z-score to be 2.91 so he concludes that he is in the 0.19 percentile
He would be in the 99.81 percentile
200
If you know Malfoy was in the 90th percentile and you know that the mean of people who took a test is 85 with a standard deviation of 4.5. Malfoy's score on this test is...
What is 90.76%
200
Percentage of data is between 2 standard deviations below the mean and 1 standard deviation above the mean
What is 81.86%
200
Calculate r
r=0.530
300
Big Picture: Difference between correlation and regression
Correlation quantifies the strength of the linear relationship between a pair of variables, whereas regression expresses the relationship in the form of an equation (Definition from National Institutions of Health)
300
WHAT IS WRONG WITH THIS
Harry ran a correlation to investigate the relationship between his time at Quitch practice and his grades on papers. His correlation coefficient is r=-0.78, so he concludes that practicing more causes his grades to drop.
Correlation does NOT equal causation
300
Rewarded house points are normally distributed with a mean of 180 points. Dumbledore rewards Gryffindor with 300 points which puts him in the 99th percentile. The standard deviation for rewarded house points is...
What is 51.58
300
You know that the mean of a data set is 4.2 and the standard deviation is 1.1. Quartile 1 would be...
What is 3.46
300
Harry wants to know the relationship between the number of mice he feeds Hedwig (x) and how long Hedwig leaves the house for his nightly fly (y).
y=5x+51.67