Final answer:
Assumption 4 in statistical analysis refers to homoskedasticity, which means that the variances in the observations of the response variable are equal across all levels of the independent variable.
Step-by-step explanation:
Assumption 4 in statistical analysis refers to the assumption of homoskedasticity. Homoskedasticity means that the variances in the observations of the response variable are equal across all levels of the independent variable.
Therefore, the correct statement about Assumption 4 is option a. Homoskedasticity means we have equal variances in the observations of the response.