AP Stats Chapter 1&4 Test Review

Front

What is the expected value in probability?

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 of occurrence.

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 a simple random sample (SRS)?

Back

A simple random sample is a subset of individuals chosen from a larger set, where each individual has an equal chance of being selected.

Front

Explain the concept of a cluster sample.

Back

A cluster sample is a sampling technique where the population is divided into clusters (groups), and a random sample of these clusters is selected. All individuals within the chosen clusters are then included in the sample.

Front

What is a stratified sample?

Back

A stratified sample is a sampling method where the population is divided into subgroups (strata) that share similar characteristics, and random samples are taken from each stratum.

Front

Define categorical variable.

Back

A categorical variable is a type of variable that can take on one of a limited, fixed number of possible values, assigning each individual or other unit of observation to a particular group or nominal category.

Front

What is a quantitative variable?

Back

A quantitative variable is a type of variable that can be measured and expressed numerically, allowing for mathematical operations.

Front

What does it mean for a distribution to be approximately normal?

Back

A distribution is approximately normal if it follows a bell-shaped curve, where most of the observations cluster around the central peak and probabilities for values further away from the mean taper off symmetrically.

Front

How do you calculate the expected number of successes in a binomial distribution?

Back

The expected number of successes in a binomial distribution is calculated using the formula: E(X) = n * p, where n is the number of trials and p is the probability of success.

Front

What is the significance of the mean in a normal distribution?

Back

In a normal distribution, the mean is the central point around which the data is symmetrically distributed, and it is also equal to the median and mode.