A teacher gives the same math exam to two different classes. The second class has more students than the first. The mean score for the first class
is 70% and the mean score for the second class is 90%. What can you say about the mean score for both classes combined?

Select one:
a. It is higher than 80%.
b. It is lower than 80%.
c. It is equal to 80%.
D.It may be higher or lower than 80%, this cannot be determined from the information given.