Confidence intervals

Point estimator

A statistic used to estimate the value of an unknown parameter in a population, often calculated from sample data.

Point estimate

A single value used to estimate a population parameter, derived from sample data.

Confidence interval

A range of values used to estimate a population parameter, with a specified level of confidence that the parameter lies within the interval.

Confidence level of C

the probability that the population parameter lies within the confidence interval, expressed as a percentage, such as 95% or 99%.

Margin of error

The maximum expected difference between the true population parameter and a sample estimate. It helps to quantify the uncertainty in the estimate.

Normal condition formula

n(1-p) >= 10 and np >= 10

10% condition

sample*10 <= population

Standard error

The standard deviation of the sampling distribution of a statistic, commonly used to measure the accuracy of a sample estimate.

Critical value (z*)

The value that corresponds to a specified significance level in a standard normal distribution, used to determine the boundaries for rejection regions in hypothesis testing.

Margin of error

The amount of error allowed in a survey or experiment result, typically expressed as a percentage. It indicates how much the sample results can differ from the population parameter.

Mean of difference of populations

p1-p2

Standard deviation of differences of populations

sqrt(p1(1-p1)/n1+p2(1-p2)/n2)