Correlations, central tendency and dispersion.

• Zero correlation- when data points on a scatter graph are randomly allocated and have no fixed fixed patter.

  
• Positive correlation- when data points on a scatter graph go in ascending order from left to right.

  
• Negative correlation- when data points on a scatter graph go descending from left to right.

  
• Correlation co efficient- a line starting with -1 on the left 0 in the middle and +1 on the right. "pearsons r"
• Central tendency- mean, median and mode.
• Dispersion - range and standard deviation(a measure of the amount of variation of the values of a variable about its mean. A low standard deviation indicates that the values tend to be close to the mean of the set, while a high standard deviation indicates that the values are spread out over a wider range)