yo know there is two type of standard deviation can you tell when to use this or that
Sure, there are two types of standard deviation: population standard deviation and sample standard deviation.
Population standard deviation is used when we have data from an entire population, meaning every member of the population is included in the dataset.
Sample standard deviation is used when we have data from a sample of the population, meaning only a subset of the population is included in the dataset. Sample standard deviation is used when we want to estimate or make inferences about the population standard deviation based on the sample data.
In general, if you have data from the entire population, you should use population standard deviation. If you have data from a sample of the population, you should use sample standard deviation.