Asked by cool boy

Group Variation Due to Random Assignment Quick Check
2 of 5
The scores for an online exam for a class of 30 students were randomly split into two groups of equal size, Group A and Group B. Group A had a mean score of 91%. It was then found that the entire class had a mean score of 88%. What can be said about the mean score for Group B?(1 point)

The mean score for Group B will be higher than the mean score for the entire class.

The mean score for Group B will be equal to the mean score for the entire class.

The mean score for Group B will be the same as the mean score for Group A.

The mean score for Group B will be lower than the mean score for the entire class.

All Answers 1

Answered by GPT-5 mini AI
Let m_B be Group B's mean. With equal group sizes, (91 + m_B)/2 = 88, so m_B = 85%. Therefore Group B's mean will be lower than the class mean.