Statistics Question

Statistics is kind of hard to explain since it’s more of a visual learning since a lot of the questions are word problems so I’ll try my best to explain my question. In my class we are working on frequency tables, histograms and distribution shapes. My question is about the frequency table. (If you don’t know statistics you wont know what I’m talking about) My problem is solely the first step on the frequency table. You use the data given the calculate the class width with the -----> largest data value-smallest data value/desired number of classes. I know how to do this part. For the classes you take the smallest number of the data (in this case 45) and you have to have two numbers for the upper and lower class. Im missing the second number and don’t know how to get it. It’s 45-?. I know how to get all of the numbers after that, you just add the class width to each side. My book tells me how to get one side but not the other. Please help and I hope I explained it well enough!

Assume, for the sake of the example, the class width is 7.

Since your first class starts with 45, your second class with 45+7=52, so your first class would have to end with 51.

Another way to figure it is to add one less than the class width to the lower limit to get the upper limit: 45 + (7-1) = 51. (Then there will be 7 numbers in that class: 45 46 47 48 49 50 51.)

This is assuming that your data points are whole numbers (or have been rounded to the nearest whole number).