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.
Why is interval estimation generally preferred over point estimation?
- Because it gives more accurate results
- Because it is easier to calculate
- Because it is less affected by outliers
- Because it provides a range of possible values rather than a single point
Interval estimation is generally preferred over point estimation because it provides a range of possible values rather than a single value. This range of values gives a better understanding of the uncertainty around the estimate, hence, it provides more information than a single point estimate.
Spearman's Rank Correlation is especially useful when the relationship between variables is ________, but not necessarily linear.
- Bimodal
- Monotonic
- Negative
- Positive
Spearman's Rank Correlation is especially useful when the relationship between variables is monotonic, but not necessarily linear. A monotonic relationship is one where the variables tend to change together, but not necessarily at a constant rate.
If the null hypothesis is true in ANOVA, the F-statistic follows a ________ distribution.
- Binomial
- Chi-Square
- F
- Normal
In ANOVA, if the null hypothesis is true, the F-statistic follows an F-distribution. The F-distribution is a probability distribution that is used most commonly in Analysis of Variance.
What does a Pearson Correlation Coefficient of 0 indicate?
- No correlation
- Perfect negative correlation
- Perfect positive correlation
- Weak positive correlation
A Pearson correlation coefficient of 0 indicates no correlation. This means that the variables are independent and there is no linear relationship between them.
What is the support of a continuous random variable?
- The highest and lowest value of the variable
- The mean value of the distribution
- The set of values that have non-zero probability
- The variance of the distribution
The support of a random variable is the set of values in the range of the variable that have non-zero probability. For a continuous random variable, it's the set of values over which the probability density function is non-zero.
How is the test statistic computed in the Sign Test?
- By averaging the ranks
- By counting the number of positive and negative signs
- By summing the differences
- By summing the ranks
In the Sign Test, the test statistic is computed by counting the number of positive and negative signs of the differences between paired observations.
In a box plot, the 'box' represents the ________ quartile range of the data.
- Full
- Inter
- Lower
- Upper
The 'box' in a box plot represents the interquartile range (IQR) of the data. This is the range within which the middle 50% of the data falls, calculated as the difference between the third quartile (Q3) and the first quartile (Q1).