Standard deviation (50 points)
dr. cwetna recorded all of the grades on a unit test on the chart below.
what is the mean and standard deviation of the distribution of individual grades? (18 points)
1. = . =
identify the following and label the dot-plot above (4 points each)
3. = and
4. = and
5. = and
find the percentage of test scores within each range listed above.
6. (4 points) does the data indicate a normal distribution?
7. (6 points) why or why not?
8. (10 points) we want to know the probability that a student selected randomly from her class would have an “a” (90 or above) in her class. find the probability. explain how to find the probability