Help please! No links! In a third grade class, students are measuring each other's heights and recording the data.

If they decide to also include their teacher's height, how would this affect the mean of their data?

A. It will have no effect on the mean.

B. It will increase the mean.

C. It will decrease the mean.

D. It will remove the mean.​

Here are the 30 best lifetime baseball batting averages of all time, arranged in order from lowest to highest: 0.319, 0.329, 0.330, 0.331, 0.331, 0.333, 0.333, 0.333, 0.334, 0.334, 0.334, 0.336, 0.337, 0.338, 0.338, 0.338, 0.340, 0.340, 0.341, 0.341, 0.342, 0.342, 0.342, 0.344, 0.344, 0.345, 0.346, 0.349, 0.358, 0.366 if you were to build a histogram of these data, which of the following would be the best choice of classes?