hypothesis

Hypothesis

An assumption, claim, or proposed explanation for an observation or phenomenon.

Null Hypothesis (Ho)

A claim that indicates the absence of relationship or difference between two values.

Alternative Hypothesis (Ha or H1)

A claim that indicates the presence of relationship or difference between values.

Hypothesis Testing

A decision-making process for evaluating or testing claims about a population based on sample information.

Level of Significance (α)

The maximum probability of committing a Type I error.

Type I Error

Occurs when a true null hypothesis is rejected, also known as an Alpha error.

Type II Error

Occurs when a false null hypothesis is accepted or not rejected, also known as a Beta error.

One-Tailed Test

A test indicating that the null hypothesis should be rejected if the test statistic is in the critical region on one side of the mean.

Two-Tailed Test

A test indicating the null hypothesis should be rejected if the test statistic is in either of the two critical regions.

Confidence Level

The probability that a parameter lies within the specified interval estimate of the parameter.

Critical Value

A value that separates the critical region from the acceptance region in a hypothesis test.

Statistic

A value obtained by using all data values of a sample from a population.

Normal Distribution

A probability distribution whose graph is continuous, bell-shaped, and symmetric.

Parameters of Normal Distribution

Mean, mode, and median are equal and located at the center, only one mode exists, symmetric about the mean, and total area is 1.

Z-test for One Sample Mean

A parametric test used for hypothesis testing when the population variance is known.

T-test for One Sample Mean

A parametric test used for hypothesis testing when the population variance is unknown.

Chi-Square Test

A nonparametric test used to assess the significance of the association between categorical variables.

Paired T-test

A parametric test comparing means from the same group at different times.

ANOVA (Analysis of Variance)

A parametric statistical method used to compare means of three or more groups.