# Determining Standard Deviation of Aggregate class data

I want to determine the standard deviation of aggregate data collected from the class to insert in a table, but have no earthly idea how to do this.

Specifically, I’ve put together an intro to Linear Regression where I have the students estimate the value of a house starting with no information then slowly giving them more and more until they have a scatterplot and a linear regression equation. At the end I want to show them how much variation there is between them on their answers and how it shrinks as they aquire additional information.

The third column for the table on slide 12 is where I’d like to put the class standard dev for each step (mathbox inputs G2 thru G8). At this point I’ve managed to learn how to derive a standard deviation of the aggregate data on the graphing calc componenet and transfer the number (sort of). But a) the std dev is listed as 8.8 which is a bit suspect, and b) when I transwer it to the table on the last slide it shows up as .707106… (which is 2^(-1/2) strangely enoulgh). If I repace the Stdev function with an integer, the integer passes without issue, but as soon as I switch it back… Can someone help me with this process. Thank you in advance.

Introduction to Linear Regression (DESMOS)

I was eventually able to solve this delema. I added a hidden graphing calculator, sent my aggregate data to the calculator, found the standard dev, and then called it from a text box. Lesson learned - I think most math needs to be accomplished inside the calculator components (someone please correct me here). There doesn’t seem to be a way to actually do CL math outside of the calculators.

Sort of.

You can do some limited math outside of the graph component with .evaluateAt and some other things, but you’re better off using the graph component for most things.