A teacher recorded the following test scores for 5 students in a class: 85, 92, 78, 90, 80.
If a new student joins the class and scores 20 on the same test, which of the following statements best describes the effect of this new score on the mean and median of the class's test scores?
Both the mean and median will decrease significantly.
The mean will decrease significantly, but the median will decrease only slightly.
The median will decrease significantly, but the mean will decrease only slightly.
Neither the mean nor the median will change significantly.
