A numerical summary of a sample, as opposed to a population, is known as a ________.
- mean
- mode
- parameter
- statistic
In the field of statistics, a statistic is a numerical summary of a sample, as opposed to a population. It's a measure that is calculated from the sample data. For example, if we have data for a certain number of individuals from a larger group, the average of this data is a statistic.
Can Pearson's Correlation Coefficient determine causality?
- No, never
- Yes, always
- Yes, but additional information is required
- Yes, but only if the coefficient is 1 or -1
No, Pearson's Correlation Coefficient cannot determine causality. It can only measure the degree of linear correlation between two variables. While two variables may be correlated, it does not mean that changes in one variable cause changes in the other. Correlation does not imply causation.
What does the range of a dataset represent?
- The average value
- The middle value
- The most frequent value
- The spread of the data
The range of a dataset is a measure of dispersion, representing the total spread of values in the dataset. It is calculated by subtracting the smallest value from the largest value in the dataset.
In a Venn diagram, the intersection of events A and B is represented by ________.
- The area only inside A
- The area only inside B
- The area outside of A and B
- The area where A and B overlap
In a Venn diagram, the intersection of events A and B is represented by the area where A and B overlap. This represents all outcomes that are in both A and B, or said another way, outcomes that satisfy both events A and B.
In which type of distribution are all outcomes equally likely?
- Exponential distribution
- Normal distribution
- Poisson distribution
- Uniform distribution
In a uniform distribution, all outcomes are equally likely. This is because the probability density function is constant within a certain range and zero elsewhere.
Does the Kruskal-Wallis Test require the data to be normally distributed?
- No
- Only for large sample sizes
- Only for small sample sizes
- Yes
No, the Kruskal-Wallis Test does not require the data to be normally distributed. This is why it is classified as a non-parametric test.
What does the term 'joint probability' mean?
- The probability of at least one of two events
- The probability of both of two events
- The probability of two independent events
- The probability of two mutually exclusive events
Joint probability is a statistical term describing the likelihood of two events happening at the same time. It's the probability of the intersection of two or more events, often denoted as P(A ∩ B) for events A and B.
In a dataset, if the _______ is zero, then all the numbers in the set are the same.
- Mean
- Range
- Standard Deviation
- Variance
If the variance of a dataset is zero, then all the numbers in the set are the same. Variance measures how far a set of numbers is spread out from their average value. If all the numbers in the dataset are identical, there would be no dispersion and the variance would be zero.
What does a Spearman’s Rank Correlation coefficient of 0 indicate?
- Data cannot be ranked
- No correlation
- Perfect negative correlation
- Perfect positive correlation
A Spearman’s Rank Correlation coefficient of 0 indicates that there is no correlation, meaning changes in one variable do not correspond to changes in the other variable.
How can undercoverage bias occur during sampling?
- By including every individual in the population in the sample
- By not including certain segments of the population in the sample
- By selecting too large of a sample
- By selecting too small of a sample
Undercoverage bias can occur during sampling if certain segments of the population are not included in the sample or are represented less than they should be. This can result in a sample that is not representative of the population, leading to biased estimates.