STATS 10 Lecture Notes - Lecture 4: Quartile, Backstroke, Missy Franklin
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Ch. 3: numerical summaries of center and variation pt. Helps us understand how the standard deviation measures variability. Ex: if a distribution is unimodal and symmetric: About 68% of observ. fall within one standard deviation of mean. About 95% of observ. fall within two standard deviations of mean. About 99. 7% of observ. fall within three standard deviations of mean. High temperatures in sf = unimodal and symmetric distribution w/mean 65 degrees & standard deviation (8 degrees) From the empirical rule we know that 95% of all days in sf = between 49 & 81 degrees. Sat scores = unimodal and symmetric w/mean of 1500 and standard deviation of 300. Mean = 1500, standard d ( ) = 300, range = 1200 - 1800. Divide -300 to -300 on opposite side of equation. Divide -300 to 300 on opposite side of equation. Comparing test scores of students from different tests (ex, sat and act)
