Basic Statistics

Basic Variables to look at when attempting to discover a new set:

N
Mean

SE Mean

StDev

Variance

CoefVar

Minimum

Q1

Median

Q3

Maximum

Range

Skewness

95% range limits: Mean ± 1.95*StdDev.

Confidence interval: The range in which we are x% sure that the population mean (also the regression line) will fall in.

(bar{x} - z^* {sigma over sqrt{n}}, bar{x} + z^* {sigma over sqrt{n}})

Prediction interval: the range in which we are x% sure that all points will fall in. It is and not influenced by the sample size n.

left[mu- zsigma, mu + zsigma right].

Statistical Model Analysis: Regression as an example:

Satistics Plots

Satistics Plots

Certain questions to answer:

i) Do the residuals appear to be systematically related to the independent variable(s)?

ii) Do the residuals appear to be roughly evenly distributed across the values of the independent variable?

iii) Do the residuals display a fairly constant variability across the values of the independent variable?

iv) Are there any serious deviations from the line expected under normality?

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