Data Management Test Wednesday!

To wrap up our Data Management Unit before the holidays, we will be having a test on Wednesday. Students have found this unit to be fairly easy, with the exception of finding the mean, median and mode. In particular, at this grade level students are given problems in which they are given the mean and a few values, and have to find one or more missing values.

I often encourage students to "work backwards" when solving these problems. For example, to find the mean, we usually use 2 steps:

1. add up all the values
2. divide by the number of values

To work backwards then, I ask them to:

1. multiply the mean by the number of values
2. subtract the values given to find the missing one. If there is more than one, then any combination that adds to the amount is fine.

Here is an example of a problem:

Herny's scores on a series of tests were: 12, 14, 15, 16 and 10. His mean score is 13. He is missing one test. What did he get on the missing test?

1. multiply: 13 x 6 = 78
2. subtract: 78-12-14-15-16-10 = 11. The missing score is 11.

Another area that students sometimes have difficulty with is constructing good survey questions. I encourage students to:

1. make sure the question is very clear
2. give a few possible answers rather than leaving the options completely open
3. ensure that only one question is being asked. You cannot ask multiple questions in one survey question. You must write another question.

Here is the Blendpace unit for Data Management. If students can do all of this well, they will have no difficulty with the test.

Data Management Blendspace