By now you are adept at calculating averages and intuitively can estimate whether something is "normal" (a measurement n
Posted: Sun Jul 10, 2022 10:10 am
By now you are adept at calculating averages and intuitively canestimate whether something is "normal" (a measurement not too farfrom average) or unusual (pretty far from the average you mightexpect). This class helps to quantify exactly how far something youmeasure is from average using the normal distribution. Basically,you mark the mean down the middle of the bell curve, calculate thestandard deviation of your sample and then add (or subtract) thatvalue to come up with the mile markers (z scores) that measure thedistance from the mean.
For example, if the average height of adult males in the UnitedStates is 69 inches with a standard deviation of 3 inches, we couldcreate the graph below.
Men who are somewhere between 63 and 75 inches tall would beconsidered of a fairly normal height. Men shorter than 63" ortaller than 75" would be considered unusual (assuming our sampledata represents the actual population). You could use a zscore to look up exactly what percentage of men are shorter than(or taller than) a particular height.
Think of something in your work or personal life that youmeasure regularly (no actual calculation of the mean, standarddeviation or z scores is necessary). What value is"average"? What values would you consider to be unusuallyhigh or unusually low? If a value were unusually high or low—howwould it change your response to the measurement?
For example, if the average height of adult males in the UnitedStates is 69 inches with a standard deviation of 3 inches, we couldcreate the graph below.
Men who are somewhere between 63 and 75 inches tall would beconsidered of a fairly normal height. Men shorter than 63" ortaller than 75" would be considered unusual (assuming our sampledata represents the actual population). You could use a zscore to look up exactly what percentage of men are shorter than(or taller than) a particular height.
Think of something in your work or personal life that youmeasure regularly (no actual calculation of the mean, standarddeviation or z scores is necessary). What value is"average"? What values would you consider to be unusuallyhigh or unusually low? If a value were unusually high or low—howwould it change your response to the measurement?