The range of a dataset is sensitive to _______.

  • Mean
  • Median
  • Mode
  • Outliers
The range of a dataset is sensitive to outliers. Because the range is calculated as the difference between the maximum and minimum values, an outlier (an extremely high or low value) can greatly increase the range.

The type of factor analysis in which the researcher assumes that all variance in the observed variables is common variance is known as _______ factor analysis.

  • common factor
  • confirmatory
  • exploratory
  • principal component
The type of factor analysis in which the researcher assumes that all variance in the observed variables is common variance is known as common factor analysis.

The Kruskal-Wallis Test is used to compare ________ independent samples.

  • four
  • three
  • three or more
  • two
The Kruskal-Wallis Test is used to compare three or more independent samples. It's an extension of the Mann-Whitney U Test for more than two groups.

In which situation is Spearman's Rank Correlation preferable to Pearson's correlation?

  • When the data is normally distributed
  • When the relationship between variables is non-linear and monotonic
  • When the relationship is linear
  • When there are no ties in the ranks
Spearman's Rank Correlation is preferable to Pearson's correlation when the relationship between variables is non-linear but monotonic. Pearson's correlation measures linear relationships, while Spearman's can capture non-linear relationships.

What is the z-value associated with a 95% confidence interval in a standard normal distribution?

  • 1.64
  • 1.96
  • 2
  • 2.33
The z-value associated with a 95% confidence interval in a standard normal distribution is approximately 1.96. This means that we are 95% confident that the true population parameter lies within 1.96 standard deviations of the sample mean.

How is the interquartile range different from the range in handling outliers?

  • Both exclude outliers
  • Both include outliers
  • The interquartile range does not include outliers, the range does
  • The interquartile range includes outliers, the range does not
The interquartile range, which is the difference between the upper quartile (Q3) and the lower quartile (Q1), represents the middle 50% of the data and is not affected by outliers. The range, on the other hand, is the difference between the maximum and minimum data values and is significantly affected by outliers.

What is the main purpose of simple linear regression?

  • To find the average of the data
  • To identify outliers
  • To understand the relationship between two variables
  • To visualize the data
The main purpose of simple linear regression is to understand the relationship between two variables. It provides a quantitative estimate of the relationship between one dependent variable and one independent variable.

In what situations is the coefficient of variation a better measure of dispersion than the standard deviation?

  • When data sets have different units
  • When data sets have the same units
  • When the data set is normally distributed
  • When the mean of the data set is zero
The coefficient of variation (CV) is a standardized measure of dispersion that is unitless. It's particularly useful when comparing the dispersion of two or more datasets that have different units or significantly different means. Standard deviation, on the other hand, has the same units as the data, which may not be helpful for comparisons across different datasets.

Under what circumstances can the conditional probability of an event be equal to its marginal probability?

  • When the event is certain
  • When the event is dependent on all other events
  • When the event is impossible
  • When the event is independent of all other events
The conditional probability of an event A given an event B equals the marginal probability of A when A and B are independent. This is because the occurrence of B does not change the probability of A if they are independent.

What type of data is the Mann-Whitney U test used for?

  • Interval data
  • Nominal data
  • Ordinal data
  • Ratio data
The Mann-Whitney U test is used for ordinal data, which can be ranked but have unknown or non-equivalent differences between values. It can also be used with interval and ratio data that do not meet the assumptions of other tests.