z-test
Definition
A z-test is a statistical test used to determine if there is a significant difference between a sample mean and a population mean when the population standard deviation is known. It compares sample data by calculating a z-value based on differences between means and their variability.
Analogy
Imagine you want to know if your school's average test score is significantly different from the national average. You collect data from your classmates, use a z-test, and compare your class's average with the known national average.
Related terms
Standard Deviation: Standard deviation measures how spread out or dispersed data points are around the mean. It helps quantify variability within a dataset and plays an important role in calculating z-values for z-tests.
Population Mean: The population mean represents the average value of an entire population. In z-tests, it serves as the reference point for comparison with sample means.
One-sample Test: A one-sample test is a statistical test used when comparing one sample mean with either a known population mean or hypothesized value. Z-tests can be conducted as one-sample tests when certain conditions are met.
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