statistics vocabulary unit 1 (chapters 1 - 6) Flashcards
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| 2942342320 | shifting | adding a constant to each data value adds the same constant to the mean, median, and quartiles, but does not change the standard deviation or IQR |  | 0 |
| 2942353525 | rescaling | multiplying each data value by a constant multiplies both the measures of position (mean, median and quartiles) and the measures of spread (standard deviation and IQR) | 1 | |
| 2956202772 | normal model | a useful family of models for unimodal, symmetric distributions |  | 2 |
| 3029915649 | context | ideally tells Who was measured, What was measured, How the data were collected. Where the data were collected, and When and Why the study was performed |  | 3 |
| 3029921843 | Data | systematically recorded information, whether numbers or labels, together with its context |  | 4 |
| 3029925494 | Case | an individual about whom or what we have data |  | 5 |
| 3034667122 | Variable | holds information about the same characteristic for many cases |  | 6 |
| 3034674128 | Categorical variable | names categories (whether words or numerals) |  | 7 |
| 3034679832 | quantitative variable | numbers act as numerical values can be measured in units |  | 8 |
| 3034686703 | units | a quantity or amount adopted as a standard measurement, such as dollars, hours or grams |  | 9 |
| 3034691854 | frequency table | lists the categories in a categorical variable and gives the count or percentage of observations for each category |  | 10 |
| 3034830029 | distribution | the possible values of the variable and the relative frequency of each variable |  | 11 |
| 3034833596 | bar chart | shows a bar representing the count of each category in a categorical variable |  | 12 |
| 3034839355 | pie chart | shows how a "whole " divides into categories by showing a wedge of a circle whose area corresponds to the proportion in the category |  | 13 |
| 3034842770 | contingency table | displays counts, and sometimes percentages of individuals falling into named categories on two or more variables |  | 14 |
| 3034848413 | marginal distribution | on a contingency table, the distribution of either variable alone or the totals found in the margins (last row or column) of the table |  | 15 |
| 3034855457 | conditional distribution | the distribution of a variable restricting the WHO to consider only a smaller group of individuals |  | 16 |
| 3034860443 | independence | the conditional distribution of one variable is the same for each category of the other |  | 17 |
| 3034867523 | histogram | uses adjacent bars to show the distribution of values in a quantitative variable. |  | 18 |
| 3034870916 | stem and leaf display | shows quantitative data values in a way that sketches the distribution of the data |  | 19 |
| 3034874526 | shape | look for: single vs. multiple modes and symmetry vs. skewness | 20 | |
| 3034878031 | center | a value that attempts the impossible by summarizing the entire distribution with a single number, a "typical" value. usually summarized with the mean or median | 21 | |
| 3034881956 | spread | a numerical summary of how tightly the values are clustered around the "center". Summarize by using the standard deviation, interquartile range, and range | 22 | |
| 3034884992 | mode | a hump or local high point int he shape of the distribution |  | 23 |
| 3034890677 | unimodal | having one mode |  | 24 |
| 3034892352 | uniform | a distribution that's roughly flat |  | 25 |
| 3034895850 | symmetric | a distribution where the two halves on either side of the center look approximately like mirror images of each other |  | 26 |
| 3034898556 | tails | the parts of a distribution that typically trail off on either side | 27 | |
| 3034902222 | skewed | a distribution that is not symmetric and one tail stretches out farther than the other |  | 28 |
| 3034905587 | outliers | extreme values that don't appear to belong with the rest of the data |  | 29 |
| 3034911597 | median | the middle value with half of the data above and below it |  | 30 |
| 3034916524 | range | difference between the highest and lowest value in a data set |  | 31 |
| 3034919247 | quartile | Q1 the value with a quarter of the data below it, Q3 has a quarter of the data above it |  | 32 |
| 3034923945 | interquartile range (IQR) | difference between the third and first quartiles |  | 33 |
| 3034925550 | 5 number summary | minimum value maximum value Q1 and Q3 median |  | 34 |
| 3034928595 | boxplot | displays the 5 number summary, effective for comparing groups |  | 35 |
| 3034929938 | mean | sum of all the data values and divided by the count |  | 36 |
| 3034933855 | variance | the sum of the squared deviations from the mean, divided by the count minus one |  | 37 |
| 3034935639 | standard deviation | the square root of the variance |  | 38 |
| 3034944880 | parameter | a numerically valued attribute of a model | 39 | |
| 3034951713 | statistic | a value calculated from the data to summarize aspects of the data | 40 | |
| 3034956569 | z score | tells how many standard deviations a value is from the mean; z scores have a mean of zero and a standard deviation of one |  | 41 |
| 3034959806 | standard normal model | a mean of zero and a standard deviation of one | | 42 |
| 3034962934 | 68-95-99.7 rule | 68% of the values fall one standard deviation from the mean 95% of the values fall two standard deviations from the mean 99.7% of the values fall three standard deviations from the mean |  | 43 |
| 3034967829 | normal percentile | gives the percentage of values in a standard Normal distribution found at that z score or below |  | 44 |
| 3034974348 | normal probability plot | helps to assess whether a distribution of data is approximately normal. the plot needs to be nearly straight to satisfy the condition |  | 45 |