Ms. murray asked her twenty students how many national parks each of them had visited. national parks visited population data 2 1 3 0 4 5 4 3 2 2 1 5 2 0 3 4 0 5 3 4 calculate the mean number of parks visited by a student from the population. round the answer to the nearest whole number.

Researchers were interested in whether relaxation training decreases the number of headaches a person experiences. they randomly assigned 20 participants to a control group or a relaxation training group and noted the change in number of headaches each group reported from the week before training to the week after training. which statistical analysis should be performed to answer the researchers' question?