Tasks 3: Examining Data by Groups
This problem continues with the same data set presented above.
Continuing from the previous findings based on the day of the sections, the professor decides to examine the data based on the actual sections: Is there a difference in the mean exam scores across the sections?
This task focuses on examining the data for assumptions. For this task, we will use a standardized score larger than 2.33 (or less than –2.33) as a flag that a given value is a potential outlier. First, calculate the sample means by group (report accurate to 2 decimal places). Then, run standardized scores for each group to classify particular scores as outliers.
For the 4 groups, the sample means are:
Which (if any) of the groups contained an outlier (defined as a z-score > 2.33 in magnitude):
Where possible, be sure to check these data sets (by group) to confirm that the assumptions for an ANOVA appear to have been met. Also, remember that there are other measures to determine if outliers are present. Though a specific one was used here, be sure to examine the other possibilities as well (e.g., boxplots).
This problem continues with the same data set presented above.
Continuing from the previous findings based on the day of the sections, the professor decides to examine the data based on the actual sections: Is there a difference in the mean exam scores across the sections?
This task focuses on examining the data for assumptions. For this task, we will use a standardized score larger than 2.33 (or less than –2.33) as a flag that a given value is a potential outlier. First, calculate the sample means by group (report accurate to 2 decimal places). Then, run standardized scores for each group to classify particular scores as outliers.
For the 4 groups, the sample means are:
Which (if any) of the groups contained an outlier (defined as a z-score > 2.33 in magnitude):
Where possible, be sure to check these data sets (by group) to confirm that the assumptions for an ANOVA appear to have been met. Also, remember that there are other measures to determine if outliers are present. Though a specific one was used here, be sure to examine the other possibilities as well (e.g., boxplots).