Parametric and Non-Parametric Tests of Independence
50 questions available
Key Points
- Measures linear relationship between continuous variables.
- Relies on the assumption of bivariate normality.
- Test statistic: t = r * sqrt(n-2) / sqrt(1-r^2).
- Degrees of freedom: n - 2.
Key Points
- Suitable for non-normal, outlier-prone, or ordinal data.
- Calculated using rank differences: r_s = 1 - [6 * sum(d^2) / (n * (n^2 - 1))].
- Uses t-statistic for hypothesis testing when n >= 30.
- Requires specialized tables for small samples (n < 30).
Key Points
- Analyzes categorical or discrete data.
- Expected Frequency = (Row Total * Column Total) / Grand Total.
- Chi-Square Statistic = Sum of [(O - E)^2 / E].
- Degrees of Freedom = (number of rows - 1) * (number of columns - 1).
- Always a right-tailed test.
Key Points
- Visualizes contingency table data.
- Tile area represents frequency.
- Standardized residual = (Observed - Expected) / sqrt(Expected).
- Shading highlights deviations from independence.
Questions
Which of the following conditions most strongly suggests the use of a non-parametric test rather than a parametric test?
View answer and explanationCalculate the degrees of freedom for a t-test of a Pearson correlation coefficient with a sample size of 25.
View answer and explanationGiven a sample correlation coefficient (r) of 0.50 and a sample size (n) of 18, what is the calculated t-statistic for testing the null hypothesis that the population correlation is zero?
View answer and explanationWhich of the following is an assumption required for the t-test of the Pearson correlation coefficient?
View answer and explanationThe Spearman rank correlation coefficient is best described as:
View answer and explanationWhen calculating the Spearman rank correlation, if two observations have the same value, how should their ranks be assigned?
View answer and explanationCalculate the Spearman rank correlation coefficient given n=5 and the sum of squared differences in ranks is 8.
View answer and explanationFor a sample size of 40, which test statistic is used to test the significance of the Spearman rank correlation?
View answer and explanationWhich test is most appropriate for determining if 'Investment Strategy' (Growth vs. Value) is independent of 'Fund Size' (Small vs. Large)?
View answer and explanationIn a contingency table, how is the expected frequency for a cell calculated?
View answer and explanationWhat are the degrees of freedom for a Chi-Square test of independence on a contingency table with 3 rows and 4 columns?
View answer and explanationConsider a contingency table cell with an Observed Frequency of 50 and an Expected Frequency of 40. What is the contribution of this cell to the Chi-Square statistic?
View answer and explanationThe Chi-Square test of independence is typically:
View answer and explanationIn a Mosaic plot, what does the size (area) of each tile represent?
View answer and explanationWhat does the standardized residual in a Mosaic plot analysis help identify?
View answer and explanationCalculate the standardized residual for a cell with Observed = 100 and Expected = 81.
View answer and explanationUnder what circumstance would the Spearman rank correlation be preferred over Pearson even if the data is continuous?
View answer and explanationWhat is the critical t-value for a two-tailed Pearson correlation test at a 5% significance level with n=25? (Approximate using standard t-distribution knowledge)
View answer and explanationA Chi-Square test results in a statistic of 15.5 with 4 degrees of freedom. If the critical value at 5% significance is 9.49, what is the conclusion?
View answer and explanationIf the Spearman rank correlation is 1.0, what does this indicate about the two variables?
View answer and explanationIn the context of hypothesis testing for correlation, the null hypothesis H0 usually states:
View answer and explanationIf a sample size is small (n < 30) for a Spearman rank correlation test, what is required to determine the critical value?
View answer and explanationCalculate the Chi-Square contribution for a cell where Observed = 20 and Expected = 25.
View answer and explanationIf a contingency table has 2 rows and 2 columns, what is the degrees of freedom?
View answer and explanationWhich of the following describes a 'Type I Error' in the context of these tests?
View answer and explanationGiven: Row 1 Total = 30, Column 1 Total = 20, Grand Total = 50. Calculate the Expected Frequency for cell (1,1).
View answer and explanationIn a Pearson correlation t-test, if the calculated t-value is 1.5 and the critical value is 2.1, what is the decision?
View answer and explanationWhen transforming data to ranks for the Spearman correlation, the smallest value is typically assigned rank:
View answer and explanationWhat is the primary advantage of using a Mosaic plot over a simple contingency table?
View answer and explanationGiven n=50 and r=0.3. Calculate the t-statistic.
View answer and explanationIf variables X and Y are independent, the population correlation coefficient rho is:
View answer and explanationWhich distribution does the Chi-Square statistic follow?
View answer and explanationIn a Spearman rank calculation, if d=0 for all pairs, then:
View answer and explanationWhat is the range of possible values for the Chi-Square statistic?
View answer and explanationIf a Chi-Square test yields a p-value of 0.03 and we use a 5% significance level, we should:
View answer and explanationCalculating Spearman rank: If Sum(d^2) = 20 and n = 6, what is r_s?
View answer and explanationWhich of the following is NOT a requirement for the Chi-Square test of independence?
View answer and explanationFor a contingency table with Row Totals of 10 and 20, and Column Totals of 15 and 15 (Grand Total 30), calculate the Expected Frequency for cell (2, 2).
View answer and explanationWhat happens to the critical t-value for a Pearson correlation test as the sample size increases (holding significance level constant)?
View answer and explanationA standardized residual of -3.0 in a Mosaic plot indicates:
View answer and explanationPearson correlation is sensitive to:
View answer and explanationIf a dataset has ranks for X: 1, 2, 3 and ranks for Y: 3, 2, 1. What is the Spearman correlation?
View answer and explanationThe null hypothesis for a Chi-Square test of independence typically asserts:
View answer and explanationWhat is the denominator in the formula for the t-statistic of the Pearson correlation?
View answer and explanationSpearman rank correlation is a specific case of:
View answer and explanationContingency table analysis is typically used for what kind of variables?
View answer and explanationIf observed frequency equals expected frequency for all cells, the Chi-Square statistic is:
View answer and explanationIn a 3x3 contingency table, what is the critical value of Chi-Square at 5% significance (approx)?
View answer and explanationWhich correlation coefficient should be used if the data is ordinal (e.g., credit ratings AAA, AA, A)?
View answer and explanationThe term 'contingency table' is synonymous with:
View answer and explanation