Confidence Intervals

These flashcards cover essential vocabulary terms related to confidence intervals and hypothesis testing, based on the lecture notes provided.

Confidence Interval (CI)

A range of values that is likely to contain an unknown population mean with a specified level of confidence.

Point Estimate

A single value that serves as an estimate of an unknown population parameter.

Sampling Error

The error that occurs when a sample statistic differs from the actual population parameter.

Margin of Error (ME)

The degree of variation between the point estimate and the actual population mean.

Degrees of Freedom (df)

The number of independent values or quantities that can be assigned to a statistical distribution.

Critical Value of t*

The t-value that corresponds to the desired level of confidence in a t-distribution.

Standard Error of the Mean

An estimate of the variability of a sample mean compared to the actual population mean.

Confidence Level

The probability that the confidence interval contains the true population mean, often expressed as a percentage.

Null Hypothesis (H0)

The hypothesis that assumes no significant effect or difference, usually denoting the status quo.

Alternative Hypothesis (H1)

The hypothesis that suggests a significant effect or difference exists, opposing the null hypothesis.

Two-Tailed Test

A statistical test that considers both directions of deviation from the null hypothesis.

Hypothesis Testing

A method of statistical inference to decide whether to reject the null hypothesis based on sample data.

CI Interpretation

Understanding that a CI indicates the probability of containing the true population mean, not that the population mean will be within the range of the CI.

Interval Estimation

A method that provides a range of plausible values for a population parameter based on sample data.

Sample Size (N)

The number of observations in a sample, which influences the precision of estimates.

Variability of Sample Means

The degree to which the means of different samples vary, impacting the width of the confidence interval.

T-distribution

A probability distribution used for hypothesis testing when the sample size is small or the population standard deviation is unknown.

Sample Standard Deviation (s)

A measure of the dispersion or variability of a sample, used in calculating confidence intervals.

Estimated Population Mean (µ)

The theoretical average of the entire population that is being estimated using sample data.