Maths Statistics

• The explanatory variable is the independent variable
• The response variable is the dependent variable
• Predictions cannot be made on the dependent variable on a line of regression, only the independent
• A test statistic is the result of tesing against a hypothesis
• Leeming is in central England
• Heathrow is in southern England
• For a continuity correction, convert less than or more than to less/more than or equal to and extend the range by 0.5
• Correlation is the type and strength of a relationship between two variables
• Bivarate data involves two variables
• A histograms area is calculated as k x frequency
• A histograms frequency density is calculated as (k x frequency) / class width
• For cumulative frequency graphs, each point at either end of a class width must be plotted
• Box plots show the smallest, largest, lower and upper quartile, interquartile range and median
• To compare box plots, compare spread (range) and the average (median) then interpret using given context
• For discrete random variable tables, probabilities must add up to 1
• For discrete uniform variable tables, all probabilities are equal and add to 1
• Interpolation of data is reliable, extrapolation of data is unreliable
• The product moment correlation coefficient shows the linear correlation between two variables
• The product moment correlation coefficient is a value between 1 and -1, the closer to 0, the less correlated the values are
• A normal distribution must be continuous and symmetrical around the mean
• For a normal distribution, 1 standard deviation covers 70% of the data, 2 covers 95% and 3 covers 100% of the data
• For normal distribution: X~N(u, o^2) u= mean o= standard deviation
• Humidity is measured in percentage
• Pressure is measured in hectopascals
• Windspeed is measured in knots
• The beaufort scale measures windspeed 0-5 with 0 being calmest and 5 being strong winds
• Daily maximum gust is the greatest windspeed over a 24 hour period measured in knots
• Mean visibility is measured in metres
• Total rainfall is measured in mm or tr for trace when <0.05 mm
• n/a in the large data set implies lack of data for that variable
• Mean daily temperature is measured in degrees celsius
• Daily sunshine is measured in hours
• Cloud cover is measured in oktas between 0-8
• Coding impacts the mean by multiplication and adding/subtracting
• Standard deviation is affected by coding only by multiplication
• The median is affected by coding by both multiplication and adding/subtracting
• The range is unaffected by coding
• Large data set has data from may-october excluding winter and spring months in 1987 and 2015
• Opportunity sampling is were people are chosen in the order you see them
• Opportunity sampling takes little time and is cost effective