# math 12

posted by
**Leigh** on
.

The mean and standard deviation of a set of data are two measurments that describe the data. A certain student has written 8 out of 10 unit exams, which are equally weighted. The student misses the ninth exam and receives a score of 0. However, for the last exam, the student studied and scored a 100%. Compare the mean and standard deviation after 8 unit tests and after 10 unit tests. My question is how do I find the mean and standard deviation when all I know is the mark on the 9th test is 0 and the tenth 100%. How do I do this question when I don't know any other marks. Please help I've never had a question with such limited information.