Finding the confidence interval with a set of x's and y's

[jeffreybrown]

I Have a set of data for making a scatter diagram.

X	Y
32	2
33	3
34	3
35	2
36	4
37	6
38	3
39	4

<colgroup><col width="72" span="2" style="width:54pt"> </colgroup><tbody>
</tbody>

I've been looking into the formula =CONFIDENCE(alpha,standard_dev,size) to set the confidence values, but just not understanding how to apply it.

I know the "alpha" in my case will by 0.05 and the size is 8, but not finding any joy on the 2nd argument, standard_dev.

I've used the stdev formula, but evidently not not applying it correctly on data with x's and y's.

With the analysis toolpak I get...

Lower 95% - -0.1426
Upper 95% - 0.7378

 

[mcmahobt]

Are you expected to create a linear regression model with X and Y? If so, you can solve for your standard deviation since you're given your alpha and sample size .

 

[jeffreybrown]

Yes I am creating a linear regression model with this data.

So what can I use to solve for the standard dev?

 

[mcmahobt]

Without diving into a full on stats lesson as to not misinform you, I'd say have a look at this link Introduction to Linear Regression. It goes into some examples of simple linear regressions and should point you in the right direction.

If you need more help, just let me know.

 

[shg]

Sorry, Jeff, I know nothing about this. When Petunia goes to college, I'm going to go with her and major in statistics.

 

[jeffreybrown]

Thanks shg...sign me up too...