Statistics Exam 1

 z-score: represents number of standard deviations a data value falls above or below the mean. z= (X-μ)/σX= scoreμ= meanσ= standard deviation Percentile: divides a distribution into 100 equal parts. Percentile= [((# of values less than X) + .5)/total # of values] * 100% Outlier: extremely high or low value in a set of data Normal graph: Bell-shaped Normal Rule: given to a normal (bell-shaped) distribution | | | | I | | | | [ 68%] [ 95% ] [ 99.7% ] Stem and leaf plot: First digit on one side, second digit(s) on the other side.ex.: 18 24 25 28 39 45 46 46 49 1 | 82 | 4 5 83 | 94 | 5 6 6 9 Nominal No orderex: religion, race, hair color, gender Ordinal: low detail orderex: sequels, seasons, grades, months, alphabet Intervals: High detail oorder, 0≠ nothingex: temperature, clock time, years, IQ Ratio: high detail order, 0= nothingex: height, speed, salary, age Categorical: -class-frequency-percent Ungrouped: -class-class boundaries (the x.5 numbers above and below each class)-frequency-cumulative frequency (total up to a certain point; add number from the class before) *list classes not listed or classes in between Grouped: -class-class boundaries (x.5 above and below number)-frequency-cumulative frequency (add frequency from class before)-relative frequency (frequency÷total from cumulative frequency)-cumulative relative frequency Histogram: bar graph Frequency polygon: line graph that originates from 0 before first value and ends at 0 after last value. cumulative frequency graph: line graph that originates from 0 before first value and ends with a horizontal line after last value. Nominal: ordinal: interval: ratio: modemedian(symmetrical) mean; (skewed) median(symmetrical) mean; (skewed) median Pareto chart: bar graph used to show frequencies for nominal or qualitative variables. Time series graph: line graph used to show a pattern or trend that occurs over a period of time. Doesn't originate from 0 and ends at last value. Pie graph: used to show the relationship between the parts and the whole. Mean (μ) rounding rule: round to one more decimal place than occurs in the raw data. Midrange: average of highest and lowest value. Weighted Mean: sum of (weights*values)÷sum of weights Variance: the average of the squares of each value's distance from the mean. σ^2 ex: (0+2+0+0+1+1+0)^2 ÷ 7σ^2= 6/7 Standard deviation: the square root of the variance. σ rounding rule for variance and standard deviation: round to one more decimal place than occurs in raw data If the word "sample" is used in description: while doing the mean, subtract 1 from the bottom number in the division. ex: 0+4+0+0+1+1+0 ÷ 7-1variance: s^2= 6/6= 1std. deviation: s= 1 the coefficient of variation: CVar= (σ ÷ μ) * 100%μ: meanσ: std. deviation When comparing two variations, the higher number is more variable. AuthorAnonymous ID72615 Card SetStatistics Exam 1 Descriptionread title Updated2011-03-13T20:49:50Z Show Answers