Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
STTN Test 2
Ch 4-6
| Term | Definition |
|---|---|
| Parameter | Summarising value calculated from a whole population |
| Statistic | Summarising value from a sample |
| Measure of location/position | Potray the centre of population or sample by a single number |
| Arithmic mean | Gemiddeld x bar Continues assumption: all observations appear at class midpoint |
| Mode | value with highest incidence |
| Modal interval | interval with highest f |
| Median | Middle/center of data set if arranged from smallest to largest |
| Quartiles | Divides data in 4 parts |
| Deciles | Divides data in 10 parts |
| Percentiles | Divides data in 100 parts |
| Symmetrical distribution | Left is mirror image of right Mean = mode = median |
| Skewed right/ positive | Slopes down from left to right - slide right mean>median>mode |
| Skewed left / negative | Slides left, slopes down from right to left mode>median>mean |
| Range | difference between max and min observations |
| Interquartile range | qr = q3-q1 |
| Quartile deviation | qd=qr/2 |
| Standard deviation | gives mean distance of obs from arithmetic mean |
| Sample variance | s^2 |
| Sample standard deviation | s |
| Coefficient of variation | Standard dev as % of the mean v=s/x *100 |
| Stem and leaf plot | Summarised image of data Stem: first number Leaf: last numbers |
| Five number summary | Min; Q1; Median; Q3; Max |
| Box plots | Based on 5-number summary |
| Turkey's rule | Outlier is a value more than 1.5 times the interquartile range q1-1.5qr OR q3+1.5qr |
| Relative frequencies | r=f/n |
| Scatterplot | values of independent variables are plotted against dependent variables |
| Correlation | Linear relationship between 2 variables |
| Pearsons Correlation coefficient | measures degree of linear relationship between two variables r=sxy/sxsy |
| Properties of Correlation coefficient | x-1<=r<=1 r>0: positive relationship r<0: negative relationship r=1: PERFECT positive r=-1: PERFECT negative r=0: NO linear realtionship |
| Regression | Determine relationship between x and y & to predict values |
| Regression eq | y=alpha+betha(x)+e |
| Estimated regression ew | y=a+bx |
| Method of least squares | "Best" regression line to fit data Vertical distances between data points are as small as possible |
| Residual | Diff between observed value and value given by estimated regression line |
| Interpolation vs Extrapolation | Inter: estimate y for x INSIDE interval Extra: estimate y for x OUTSIDE interval |
| Coefficient of determination | R^2 indication of how well least-squares curve fits observed data Linear: r^2 = R^2 |
| Properties of R^2 | 0<=R^2<=1 R^2 = 1: perfect fit R^2 = 0: doesn't fit at all straight line: R^2 = r^2 |
Created by:
CARA.FAURIE
Popular Math sets