I need help please help me

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.

Can you me find the missing length. i attached an image.

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?