# STAT QUIZ SHEET - Outliers: Greater than Q3 + 1.5 IQR, or...

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Outliers: Greater than Q3 + 1.5 × IQR, or Smaller then Q1 - 1.5 × IQR , Standard Deviation: find the difference between the value and the mean, Add the squared deviations found and divide by (n – 1) (Variance), Take square root of value found. Scatter plot: a two-dimensional graph of data values for two quantitative variables, Correlation: a statistic that measures the strength and direction of a linear relationship between two quantitative variables, Regression equation: an equation that describes the average relationship between a quantitative response variable and a quantitative explanatory variable, Regression analysis : is concerned with finding the 'best' fitting line for predicting the average value of a response variable y using a predictor variable x. Residuals: are the errors made in the predictions. For example, for x = 3, the predicted value is 4.50 and the observed value of x is y = 5.0, so the residual is 5.00 - 4.50 = 0.50. R 2 = (SSTO - SSE) / SSTO, Residual, also called a prediction error is the difference between an actual value of y and a predicted value of y. Correlation coefficient , sometime called the Pearson correlation , is a statistic that measures the direction and strength of a liner (straight-line) relationship. (Correlation coefficient is represented by the letter r , It always has a value between -1 and +1. The stronger (more predictable) the relationship is, the

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## This note was uploaded on 07/13/2008 for the course STAT 200 taught by Professor Barroso,joaor during the Fall '08 term at Pennsylvania State University, University Park.

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STAT QUIZ SHEET - Outliers: Greater than Q3 + 1.5 IQR, or...

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