Descriptive statistics
Values that describe the xtics of a sample/popn
1) Organize, categorize and summarise data
2) Determine if sample is normally distributed (Bell curve) & can be compared to a larger popn
3) Displayed as tables, charts, percentages, frequency distributions (eg piecharts, histograms)
4) Reported as measures of central tendency eg mean, mode, median and measures of variability eg range, variance, standard deviation
Skewness How symmetrical the distribution of the variables are
+vely skewed, where the tail of the graph extending to the right(Mean>Median)
-vely skewed, where the tail of the graph extending to the left (Mean<Median)
Kurtosis
Peakedness (A lot of the sample is very similar)
Flatness (Wide distribution of different subjects in the sample) of a distribution
Measures of Variability
Range: Difference between the highest and the lowest variables.
Variance: How far apart are the numbers.
Standard Deviation: How much variation exists from the average/mean
Shape if there is a frequently occurring number, outliers, even skewness
-