# Statistics Chapter 3b

 What are z-scores often called? Standardized scores What can a z-score tell you? How many standard deviations a value is from the mean What is the z-score equation? What is the mean of a z-score? 0 What is the standard deviation of a z-score? 1 What does the +/- mean terms of z-scores? + value means how many standard deviations ABOVE the mean- value means how many standard deviations BELOW the mean What does the Empirical rule apply to? Data that is "normally distributed"Example: skewness = 0, mean median What are the 3 parts to the Empirical rule? 68% of the values will be between z = -1 and z = +195% of the values will be between z = -2 and z = +299.7% of the values will be between z = -3 and z = +3 What are outliers? Unusually small or large values in a dataset What z-scores do outliers typically have? z < -3 or z > +3 What could be the cause of an outlier? ErrorEvidence of something unusual What does covariance measure? Linear associate between 2 variables What is the covariance equation for a sample statistic? What is the covariance equation for a population parameter? For a covariance, what does the sign tell you? Positive = direct relationshipNegative = inverse relationship For a covariance, what does the value tell you? Nothing What is the correlation coefficient equation for a sample statistic? What is the correlation coefficient equation for a population parameter? What does the correlation coefficient measure? The strength of the relationship How strong is the relationship for two variables with a correlation coefficient of .30? Weak How strong is the relationship for two variables with a correlation coefficient of .50? Moderate How strong is the relationship for two variables with a correlation coefficient of .80? Strong How strong is the relationship for two variables with a correlation coefficient of .90? Very strong Authorhonestkyle ID198125 Card SetStatistics Chapter 3b DescriptionStandard deviation and variance calculations. Things are getting more difficult. Updated2013-04-11T16:17:03Z Show Answers