For this discussion post, we will practice learning and sharing our examples on

For this discussion post, we will practice learning and sharing our examples on confidence intervals. We will complete the following tasks.
First, pick a number for xbar between 60-100. Pick a number for s between 4-8. Find the confidence interval which is given by xbar +/- E.
Next, we will consider what happens when we change n.
On the first one, we will have a 95% confidence interval with z=1.96 and n=100.
For the second one, we will have a 95% confidence interval with z=1.96 and n=400.
Since you have a 95% confidence interval alpha = 100%-95% =5% or .05 as a decimal.
Here is a short cut to use excel!!!
This is a z score example, so to find E we use the formula
=confidence.norm(alpha, sd, n).
In this case you will type this in an excel cell to find E and then take the =xbar + E and =xbar – E, which is the confidence interval.
Show both intervals and the numbers you used. Why do you think they changed?
(Please note, that if you had a t-test where n< 30 then use the following formula:
=confidence.t(alpha,sd,n) to find E.)
Please remember that you need to post your initial response by Thursday night at midnight. Then please respond to at least two of your classmates by Sunday night at midnight.
You will earn 6 points for a well-thought-out initial response to the discussion question and 4 points for well-thought-out responses to your classmates.