<< Chapter < Page | Chapter >> Page > |
Data from Graduating Engineer + Computer Careers. Available online at http://www.graduatingengineer.com
Data from Microsoft Bookshelf .
Data from the United States Senate website, available online at www.Senate.gov (accessed June 17, 2013).
“List of current United States Senators by Age.” Wikipedia. Available online at http://en.wikipedia.org/wiki/List_of_current_United_States_Senators_by_age (accessed June 17, 2013).
“Sectoring by Industry Groups.” Nasdaq. Available online at http://www.nasdaq.com/markets/barchart-sectors.aspx?page=sectors&base=industry (accessed June 17, 2013).
“Strip Clubs: Where Prostitution and Trafficking Happen.” Prostitution Research and Education, 2013. Available online at www.prostitutionresearch.com/ProsViolPosttrauStress.html (accessed June 17, 2013).
“World Series History.” Baseball-Almanac, 2013. Available online at http://www.baseball-almanac.com/ws/wsmenu.shtml (accessed June 17, 2013).
Two population means from independent samples where the population standard deviations are not known
Standard error: SE =
Test statistic ( t -score): t c =
Degrees of freedom:
where:
and are the sample standard deviations, and and are the sample sizes.
and are the sample means.
Cohen’s d is the measure of effect size:
where
Use the following information to answer the next 15 exercises: Indicate if the hypothesis test is for
It is believed that 70% of males pass their drivers test in the first attempt, while 65% of females pass the test in the first attempt. Of interest is whether the proportions are in fact equal.
two proportions
A new laundry detergent is tested on consumers. Of interest is the proportion of consumers who prefer the new brand over the leading competitor. A study is done to test this.
A new windshield treatment claims to repel water more effectively. Ten windshields are tested by simulating rain without the new treatment. The same windshields are then treated, and the experiment is run again. A hypothesis test is conducted.
matched or paired samples
The known standard deviation in salary for all mid-level professionals in the financial industry is $11,000. Company A and Company B are in the financial industry. Suppose samples are taken of mid-level professionals from Company A and from Company B. The sample mean salary for mid-level professionals in Company A is $80,000. The sample mean salary for mid-level professionals in Company B is $96,000. Company A and Company B management want to know if their mid-level professionals are paid differently, on average.
Notification Switch
Would you like to follow the 'Introductory statistics' conversation and receive update notifications?