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Two Means - Unknown, Equal Variance definitions

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Termini in questo insieme (15)

  • Pooled Standard Deviation
    A weighted average of two sample variances, used to estimate a common population standard deviation when variances are assumed equal.
  • Equal Variance Assumption
    The premise that two populations have the same variance, allowing for more precise statistical testing using pooled data.
  • Hypothesis Test
    A structured process for deciding if sample data provides enough evidence to support a specific claim about population parameters.
  • Null Hypothesis
    A statement asserting no difference or effect, typically that two population means are equal.
  • Alternative Hypothesis
    A claim suggesting a difference or effect exists, such as one mean being greater than the other.
  • Test Statistic
    A calculated value, often a t-score, used to determine how far sample results deviate from the null hypothesis.
  • P-value
    The probability of observing results as extreme as those in the sample, assuming the null hypothesis is true.
  • Alpha Level
    A threshold probability, often 0.05, used to decide whether to reject the null hypothesis.
  • Degrees of Freedom
    A value based on sample sizes, used to select the correct distribution for hypothesis testing.
  • Independent Samples
    Groups selected so that the outcome of one does not influence the outcome of the other.
  • Sample Mean
    The average value calculated from a group, representing the central tendency of the sample.
  • Sample Standard Deviation
    A measure of variability within a sample, indicating how spread out the data points are.
  • T-table
    A reference chart used to find probabilities and critical values for t-distributions based on degrees of freedom.
  • Normal Approximation
    An approach where large sample sizes allow the use of normal distribution properties for inference.
  • A/B Test
    A comparison of two groups to determine if a change or treatment leads to a statistically significant difference.