Semester Review Stat Lab Flashcards
(1.2) Parameter
Describes some characteristic of a population (a population of x…)
(1.2) Statistic
Describes some character of a sample ( x of x amt, percentages, means)
(1.2) Discrete
Countable; only takes on specific values (# of t shirt sizes)
(1.2) Continuous
Infinite; can take on many values (weight, area, mass)
(1.2) Nominal
Categories, names, and labels only; can’t be arranged in order (ex: music genres, gender, etc.)
(1.2) Ordinal
can be arranged in order; differences in data can’t be determined or are meaningless (ex: movie ratings, letter grades, rankings)
(1.2) Interval
like ordinal, but difference btwn data value matters; doesn’t have natural zero starting point (not necessary the absence of any data) (ex: temperature, years, etc.)
(1.2) Ratio
like interval, but there is a natural zero starting point; differences & ratios matter (ex: money, height, age)
(2.1) Outliers
Sample values that lie very far away from the majority of the other sample values
(2.1) Distribution Shape
Normal = bell-shaped
Longer right tail = data skewed to right
Longer left tail = data skewed to left
(2.1) Outlier on histogram…
… will appear as a bar far from all the others w/ a height corresponding to 1
(2.1) Histogram
Graph w/ equal-width bars next to each other
(horizontal = quantitative classes; vertical = frequencies)
(find n by adding bars together)
(3.1) Mode
Measure of center w/ value that occurs with greatest frequency
(3.1) Median
middle value when original data values are in increasing / decreasing order; resistant
(3.2) Standard Deviation Properties
(1) unit of SD are same as units of original data
(2) measure of variation of all data values from the mean
(3) never negative
Variance
Square of the standard deviation
(3.3) Z-Score Properties
- no units of measurement (in., cm.)
- above of below mean
- significantly high or low (2 <p< -2)
- Greater than mean = +; Less = -
(3.3) Range Rule of Thumb
Value (x) -/+ (1,2,3…) standard deviation
- significantly high (+) or low (-)
(3.3) Z-Score
How many standards deviations away it is from the mean (round to two decimal places); x - x̄/SD
(3.1) Mean
sum of data values / # of values; non-resistant
(3.1) midrange
Max - min value /2
(3.3) Percentiles
kth percentile being used (k = 25) (ex: 66th percentile = .66 to its left, or 66%)
(4.1) Relative Freq Approx of Probability
P(a) = # of ways A occurred (x) / # of times experiment repeated (n)
(4.1) Classic Probability
P(a) = # of way A can occur (s) / # of different simple events (n)
