Studied by 13 people
z-score
tells us how many standard deviations from the mean an observations falls, and in what direction (value - mean / SD)
percentile
the value with p% of observations LESS THAN OR EQUAL to it
Cumulative relative frequency graph
plots a point corresponding to the percentile of a given value in a distribution of quantitative data
Transforming
converts the original observations from the original units of measurements to another scale
Density Curve
the area under this curve and above any interval of values on the horizontal axis estimates the proportion of all observations that fall in that interval
Mean of a Density Curve
the point at which the curve would balance if made of solid material
Median of a Density Curve
the equal-areas point, the point that divides the area under the curve in half
Normal distribution
described by a symmetric, single-peaked, bell-shaped density curve called a NORMAL CURVE
Empirical Rule (68-95-99.7)
in a normal distribution, ~68% of observations fall within 1 SD of the mean, ~95% of observations fall within 2 SD of the mean, and ~99.7% of observations fall within 3 SD of the mean
Sample Normal Distribution
the normal distribution with mean 0 and SD 1 —- use when referring to z-scores
Standard Normal distribution
the normal distribution with mean 0 and SD 1 (use when referring to z-scores)
