Term
| Measures of Central Tendency |
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Definition
| Mean, median, and mode are values that describe the center of a data set. |
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Definition
| center of a data set. Mean The sum of the values in a set divided by the number of values, usually seen as x¯ |
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| When a set is ordered numerically, the middle value or the mean of the two middle values. |
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| The value or values that occur most often. A data set may have no mode, one mode, or several modes. |
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| Shows the spread of a data set for 5 key points: the minimum and maximum values, the median, and the first and third quartiles. |
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| The medians of the lower and upper halves of the data set. If there are an odd number of data values, do not include the median in either half. |
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Definition
| IQR is the difference between the 1st and 3rd quartiles, the middle 50% of the data. |
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| A data value that is substantially different from the rest of the items in the data set. |
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| Describe how the data in a data set are spread out (range, interquartile range, standard deviation). |
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| The difference between the greatest and least values. |
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Definition
| IQR is the difference between the 1st and 3rd quartiles, the middle 50% of the data. |
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Definition
| A measure of how each value in a data set varies, or deviates, from the mean. The Greek letter (sigma) represents standard deviation. |
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| A number that describes or summarizes a sample |
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Definition
| A number that describes a population |
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Definition
| Gathers information from only part of a population |
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| An estimate of error in sample proportion based on the standard deviation. The larger the sample size, the smaller the margin of error. |
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Definition
| The ratio of the number of times an event occurs, x, to the sample size, n. |
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Definition
| Each individual in the population has an equal chance of being selected. |
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Definition
| Members volunteer to participate. |
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| Members are chosen because they are easily accessible |
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| Members are chosen using a rule, such as every nth person in the population. |
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| The population is first divided into groups. Then members are randomly chosen from each group. |
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Term
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Definition
| The population is first divided into groups. A sample of the groups is randomly chosen. |
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