Confidence Interval

Using my previously collected data, I will perform a 95% confidence interval. This is how I performed this interval.

First:

Excel command: =T.INV(1-0.05/2,29)

= 2.045

Second: I had to calculate the margin of error. This is how:

Standard Deviation: 0.856 (I got this calculation from the last part of my project)

Excel command: CONFIDENCE.T(0.05,0.856,30)

E=0.319

Third:

Sample mean: 2.609 (I got this calculation from the last part of my project as well)

2.609-0.319=2.289

2.609+0.319=2.929

2.289

With this being calculated, my parameter of 3.659 does not fall between this interval. This means that the value 3.659 is not a reliable interpretation of being the average price of chocolate chip cookies. It also means there is a statistically significant difference between the groups. It could also imply that I am not 95% confident it is the correct price.

Conduct a hypothesis test with your sample data using significance level of 0.05. State your claim to use a left tail or right tail test. If your sample statistic is lower than your population parameter, use a left test. If your sample statistic is higher than your popular parameter, use a right tail. In context of your chosen topic, what is the conclusion?

The 3.659 is the population mean.