Exam 1 STAT-218

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What is a symmetric distribution?

Back

A symmetric distribution is a probability distribution where the left side of the distribution is a mirror image of the right side. Examples include the normal distribution.

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What is a z-statistic?

Back

A z-statistic is a type of standardized statistic that indicates how many standard deviations an element is from the mean of a distribution, used when the population variance is known.

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What is a categorical variable?

Back

A categorical variable is a type of variable that represents qualitative attributes or categories, such as gender, color, or type of car.

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What is a quantitative variable?

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A quantitative variable is a type of variable that represents numerical values or quantities, such as height, weight, or age.

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What is a t-statistic?

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A t-statistic is a type of standardized statistic used to determine if there is a significant difference between the means of two groups, especially when the sample size is small and the population variance is unknown.

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What is the purpose of hypothesis testing?

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Hypothesis testing is a statistical method used to make decisions about the validity of a hypothesis based on sample data.

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What is a null hypothesis?

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The null hypothesis is a statement that there is no effect or no difference, and it serves as the starting point for statistical testing.

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What is an alternative hypothesis?

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The alternative hypothesis is a statement that indicates the presence of an effect or a difference, opposing the null hypothesis.

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What is a p-value?

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A p-value is the probability of obtaining test results at least as extreme as the observed results, assuming that the null hypothesis is true.

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What does it mean if a p-value is less than 0.05?

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If a p-value is less than 0.05, it typically indicates that the results are statistically significant, leading to the rejection of the null hypothesis.