population
A population survey, better known as a census, entails the collection of each unit in the population. In sample survey information is collected from a subset of the population. The subset, or sample, needs to be selected carefully so that it is representative of the whole population and, if that requirement is met, statistics based on the sample are good estimators for the corresponding population parameters.
If the sample is not representative of the population, then the characteristics of the sample are not the characteristics of the population. Example: If I want to estimate the percentage of the population that are men, and my sample is the school's football team, my estimate would be that 100% of the population is comprised of men. What went wrong with my survey ? Simple. The football team is not a representative sample of the population, at least not as regards gender.
sample size refers to the collection of data by only a selected size of te population through the process of sample surveys and sampling methods used in collecting data.
The sample is a subset of the population. For example, the population may be all the people at your school. A sample might be 5 people from each class. There are different types of sampling methods. The most commonly used is a simple random sample. When your obtain data from the entire population this is called a census.
A sample is a subset of the population.
A population is the collection of all of the units of interest to a researcher. A sample is a subset of this collection that the researcher selects that is typically smaller than the population.
The entire population.
A population survey, better known as a census, entails the collection of each unit in the population. In sample survey information is collected from a subset of the population. The subset, or sample, needs to be selected carefully so that it is representative of the whole population and, if that requirement is met, statistics based on the sample are good estimators for the corresponding population parameters.
The population consists of every possible unit where a sample is a subset of the population. Note that population and sample need not refer to persons. For example, if studying biodiversity, the population could consist of plots of land.
If the sample is not representative of the population, then the characteristics of the sample are not the characteristics of the population. Example: If I want to estimate the percentage of the population that are men, and my sample is the school's football team, my estimate would be that 100% of the population is comprised of men. What went wrong with my survey ? Simple. The football team is not a representative sample of the population, at least not as regards gender.
sample size refers to the collection of data by only a selected size of te population through the process of sample surveys and sampling methods used in collecting data.
The sample is a subset of the population. For example, the population may be all the people at your school. A sample might be 5 people from each class. There are different types of sampling methods. The most commonly used is a simple random sample. When your obtain data from the entire population this is called a census.
No, it is not true. All that a sample gives you is an estimate about what the distribution might look like in the entire population. If you know what the distribution in the population looks like you have an error free fact and no estimate can better than that. another way to look at that: the bigger a sample gets the better the accuracy of the estimate. The sample cannot be bigger than the population however. The one caveat is in the data collection process. Under certain circumstances a sample may be more precise when data collection is difficult or flawed.
A point estimate of a population parameter is a single value of a statistic. For example, the sample mean x is a point estimate of the population mean μ. Similarly, the sample proportion p is a point estimate of the population proportion P.
A Sample
A sample is a subset of the population.
You are studying the sample because you want to find out information about the whole population. If the sample you have drawn from the population does not represent the population, you will find out about the sample but will not find out about the population.