AP Stats Cumulative Review #2

Front

What is the correlation coefficient (r) and what factors can affect its value?

Back

The correlation coefficient (r) measures the strength and direction of a linear relationship between two variables. None of the options provided in the context can affect the r-value.

Front

How do you determine the required sample size for a survey at a specific confidence level and margin of error?

Back

To determine the required sample size for a survey, you can use the formula: n = (Z^2 * p * (1-p)) / E^2, where Z is the Z-score corresponding to the confidence level, p is the estimated proportion, and E is the margin of error. For a 95% confidence level and a margin of error of 3%, a sample size of 1068 is needed.

Front

What is the effect of adding a constant value to all data points on the mean and standard deviation?

Back

Adding a constant value to all data points increases the mean by that constant but does not affect the standard deviation.

Front

What factors contribute to a narrower confidence interval?

Back

A narrower confidence interval can be achieved by having a large sample size and a lower confidence level.

Front

What is the definition of variability in statistics?

Back

Variability refers to how spread out or dispersed the values in a data set are. It can be measured using various statistics, such as range, variance, and standard deviation.

Front

What is the significance of percentiles in a data set?

Back

Percentiles indicate the relative standing of a value within a data set, showing the percentage of data points that fall below that value.

Front

How does sample size affect the margin of error in a confidence interval?

Back

As the sample size increases, the margin of error decreases, leading to a more precise estimate of the population parameter.

Front

What is the relationship between confidence level and the width of a confidence interval?

Back

As the confidence level increases, the width of the confidence interval also increases, meaning you are more certain that the interval contains the population parameter.

Front

What is the formula for calculating the standard deviation of a data set?

Back

The standard deviation (σ) is calculated using the formula: σ = √(Σ(xi - μ)² / N), where μ is the mean, xi represents each data point, and N is the number of data points.

Front

What is the purpose of hypothesis testing in statistics?

Back

Hypothesis testing is used to determine whether there is enough evidence in a sample of data to support a specific claim or hypothesis about a population.