week four Flashcards
what is a continuous variable?
a continuous variable is one that can take a value between the upper bound and lower bound, form zero to infinity.
what is a frequency distribution?
a tabular summary of a dataset showing the frequency of items in each of several non-overlapping classes.
what does kurtosis mean?
degree of weakness or steepness of a data.
what does a symmetrical distribution tell us?
all the measures of central tendency are the same: mean, median and mode.
what are measures of central tendency?
describes the central position of a dataset
what is mean?
it is the average and expected value.
what are the three types of mean?
harmonic mean
geometric mean
arithmetic mean
what is median?
median is the value that separates the data in two equal parts
it is a perfect measure of central location
what is a density curve?
it is an idealised description of a data set. while it describes the distribution of a data set, it always has an area of zero and lies above the horizontal axis
what is variance?
variance tells us how spread out the data is from the average
what does the standard deviation tell us?
it tells us the variation of values in a data set
a low one tells us that the data is closer to the mean whereas a higher one tells us its more spread out from the mean
it is the square root of variance
