I need help with this

On a architect's drawing of a house, 1 inche representa 1.5

Use set buikder notation to represent the following set: {, -2, -1, 0}

()1. how do you find range? 2.the following set of data is to be organized into a histogram. if there are to be five intervals on the graph, what should the length of each interval be? 30, 34, 23, 21, 27, 25, 29, 29, 25, 23, 32, 31