Physics Ch 12. Data and Statistical Reasoning Flashcards
Measures of central tendency
Provide a single value representation for the middle of a group of data
Arithmetic mean
aka average, measure of central tendency that equally weighs all values, it is affected by outliers
Median
The value that lives in the middle of the data set, 50% of the data points are above and below the median
Mode
Data point that appears most often, there may be multiple or zero modes in the data set
Normal distribution
Symmetrical, the mean, median, and mode are all the same in the normal distribution
Standard distribution
A normal distribution with a mean of zero and a standard deviation of one, it is used for most calculations, 68% of data points occur within one SD, 95% within 2, and 99% within 3
Skewed distributions
Have differences in their mean, median, and mode, the skew direction is the direction of the tale of the distribution
Bimodal distributions
Have multiple peaks, although not necessarily multiple modes, it may be useful to performed out analysis on the two groups separately
Range
Difference between the largest and smallest value in the data set
Interquartile range
The difference between the value of the third quartile and first quartile, interquartile range can be used to determine outliers
Standard deviation
A measurement of variability about the mean, standard deviation can also be used to determine outliers
Outliers
May be a result of a true population variability, measurement error, or non-normal distribution, procedures for handling outliers should be formulated before the beginning of a study
Independent events
The probability of independent events does not change based on the outcomes of other events
Dependent event
Probability of a dependent event changes depending on the outcomes of other events
Mutually exclusive outcomes
Cannot occur simultaneously
