What is the primary purpose of conducting an ANOVA test?
- To calculate the standard deviation of a dataset
- To determine the mode of a set of data
- To find the correlation between two variables
- To test the equality of means among groups
The primary purpose of an ANOVA test is to compare the means of different groups and determine whether any of those means are significantly different from each other.
How is the confidence interval for a proportion calculated?
- nan
- p ± (z*√(p(1-p)/n))
- p ± z*(s/√n)
- p ± z*(σ/√n)
The confidence interval for a proportion is calculated using the formula: p ± (z*√(p(1-p)/n)), where p is the sample proportion, z is the z-score associated with the desired confidence level, and n is the sample size.
What is the relationship between Cramér's V and the Chi-square test?
- Cramér's V is the inverse of the Chi-square statistic
- Cramér's V is the square of the Chi-square statistic
- Cramér's V is the square root of the Chi-square statistic divided by the sample size and the minimum of rows and columns minus 1
- There is no relationship between Cramér's V and the Chi-square test
Cramér's V is a measure of association between two nominal variables and it is based on the Chi-square statistic. It is calculated as the square root of the Chi-square statistic divided by the sample size and the minimum of rows and columns minus 1.
What kind of data is suitable for the Kruskal-Wallis Test?
- Binary data
- Nominal data
- Normal data
- Ordinal or continuous data
The Kruskal-Wallis Test is suitable for ordinal or continuous data that is not normally distributed.
The Mann-Whitney U test is primarily used for comparing ________ distributions.
- binomial
- dependent
- independent
- normal
The Mann-Whitney U test is used for comparing independent distributions, particularly to determine whether two independent samples were drawn from a population with the same distribution.
What is the difference between a discrete and a continuous probability distribution?
- Discrete distributions are always normal; continuous distributions are always uniform
- Discrete distributions are for qualitative data; continuous distributions are for quantitative data
- Discrete distributions involve countable outcomes; continuous distributions involve uncountable outcomes
- There is no difference
Discrete probability distributions are used when the outcomes are countable or discrete. Examples include the number of heads when flipping coins or the number of defective items in a batch. Continuous probability distributions are used when outcomes are uncountably infinite, typically involving measurements. Examples include the height of individuals or the time it takes to run a mile.
How does the standard deviation affect the shape of a normal distribution?
- Changes the kurtosis
- Changes the skewness
- Changes the spread or dispersion
- Does not affect the shape
The standard deviation, a measure of dispersion or spread, determines the width of a normal distribution. A larger standard deviation results in a wider, flatter distribution, while a smaller standard deviation results in a narrower, steeper distribution.
A _______ t-test is used to compare two related samples or repeated measurements on a single sample.
- Independent
- One-sample
- Paired
- Two-sample
A Paired t-test is used to compare two related samples or repeated measurements on a single sample. It's often used in before-and-after scenarios where the same individuals are measured twice.
What is a random variable in probability theory?
- A factor that doesn't change
- A variable that can take on different values, each with an associated probability
- An unknown variable
- An unpredictable factor
A random variable in probability theory is a variable that can take on different values, each with an associated probability. It's not "random" in the everyday sense of the word, but its exact value is uncertain until it's observed.
The _________ test is a non-parametric test that compares the medians of two paired groups.
- Chi-square
- Mann-Whitney U
- Sign
- Wilcoxon Signed Rank
The Wilcoxon Signed Rank test is a non-parametric test that compares the medians of two paired groups.