9 Week Test Review Statistics

Front

What is the expected value in a probability distribution?

Back

The expected value is the long-term average or mean of a random variable, calculated as the sum of all possible values, each multiplied by its probability.

Front

Define standard deviation in statistics.

Back

Standard deviation is a measure of the amount of variation or dispersion in a set of values. A low standard deviation indicates that the values tend to be close to the mean, while a high standard deviation indicates that the values are spread out over a wider range.

Front

What is stratified random sampling?

Back

Stratified random sampling is a method of sampling that involves dividing a population into subgroups (strata) that share similar characteristics, and then taking a random sample from each stratum.

Front

Explain the concept of nonresponse bias.

Back

Nonresponse bias occurs when individuals selected for a survey do not respond, and their lack of response is related to the survey topic, potentially skewing the results.

Front

What is a binomial distribution?

Back

A binomial distribution is a probability distribution that summarizes the likelihood that a value will take one of two independent outcomes, often referred to as 'success' and 'failure', in a fixed number of trials.

Front

How do you calculate the mean of a binomial distribution?

Back

The mean of a binomial distribution is calculated using the formula: Mean (μ) = n * p, where n is the number of trials and p is the probability of success.

Front

What does it mean if a sample is said to be independent?

Back

Independent samples are those where the selection of one sample does not influence the selection of another sample, meaning the samples do not affect each other.

Front

What is the purpose of a control group in an experiment?

Back

A control group is used as a benchmark to measure how the other tested subjects do, allowing researchers to isolate the effect of the variable being tested.

Front

Define confounding variable.

Back

A confounding variable is an outside influence that changes the effect of a dependent and independent variable, leading to a false association.

Front

What is the difference between qualitative and quantitative data?

Back

Qualitative data describes characteristics or qualities (e.g., colors, names), while quantitative data represents numerical values that can be measured (e.g., height, weight).