The research question at hand is as follows: Is there a difference in the coffee consumption rate of Americans based on gender? The first Hypothesis statement is; there is a difference in the coffee consumption rate of Americans based on gender. The second Hypothesis statement is; there is not a difference in the coffee consumption rate of Americans based on gender. The team will use the Confidence Interval to check if there is no significant difference in coffee consumption levels by gender. (a) The research question is whether there is a difference in the coffee consumption rate of Americans based on gender. (b) In order to answer this question, during the month our team collected the data for 200 men and 180 women. The results were analyzed in EXCEL and the results are shown in the Appendix. Firstly, we define the two variables:

– average number of coffees/day drank by a man

– average number of coffees/day drank by a woman

Now we define the Null and the Alternative Hypothesis:

there is no difference in the coffee consumption rate of Americans based on gender there is a difference in the coffee consumption rate of Americans based on gender Now, using statistical terms, we will rewrite these hypotheses, as:

Next step is o compute the Confidence Interval of the Difference between Means. The formula is: Lower limit = Upper limit = Where and Spa= , which is called the Pooled Standard Error We will do the computations in EXCEL and get: 95% CI is:

Since we fail to reject the Null Hypothesis, and therefore we accept the Null Hypothesis. Therefore, the conclusion of the project is that there is no difference in the coffee consumption rate of Americans based on gender.

References

http://www.cliffsnotes.com/math/statistics/univariate-inferential-tests/two-sample-z-test-for-comparing-two-means http://onlinestatbook.com/2/estimation/difference_means.html http://www.answersresearch.com/means.php

http://www.scirp.org/journal/PaperInformation.aspx?PaperID=34029#.VRrsCPmUfYY