Last Minute Questions

If anyone has any last minute questions about the final just write it in here to discuss it. Id be more than willing to help if I am able to.

I am having some trouble with #11.

I remember that: T= (observation - mean ) / sample standard deviation /√. sample size.

What formula am I supposed to be using to find the standard deviation?

There is another forumula to calculate t when you are analyzing an expected mean vs. an observed mean. The formula is listed under the “retrospective and prospective looks” notes. That formula is:
t = (x - x̅ )/(s/sqrt(n))

gotcha. But which formula should I use to get s to use in that formula for t??

Henry is right about t. You compute s using the formula for sample standard deviation directly from the data.

So with number 11

You use

sigma / (sqrt(n)) To find SE
You then have to use (Mean - mu) / (SE) to find the T.Test
With this information you compare it to the critical value with the chart.