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Intro to the t-Statistic - Coggle Diagram
Intro to the t-Statistic
Estimated Standard Error
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It is computed from the sample variance or sample deviation & provides an estimate of the standard distance between a sample mean and a population mean
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t-Statistic: used to test hypotheses about an unknown population mean, when the value of the standard deviation is unknown
The formula for the t statistic has the same structure as the z-score formula, except that the t statistic uses the estimated standard error in the denominator
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Degrees of Freedom: describes the number of scores in a sample that are independent and free to vary
Sample mean places restriction on the value of one score in the sample, there are n-1 degrees of freedom for a sample with n scores
Greater value of df for a sample, the better the sample variance represents the population variance & the better the t statistic approximates the z-score
the larger the sample (n), the better the sample represents its population
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t-Statistic Distribution: complete set of t values computed for every possible random sample for a specific sample size (n) or a specific degrees of freedom (df)
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Shape of Distribution
As the degrees of freedom gets larger, the more it looks like a normal distribution
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