1) In January 1971, a Gallup Poll asked, "A proposal has been made in Congress to require the US government to bring home all US troops before the end of the year. Would you like to have your congressman vote for or against this proposal?" Guess the results, for respondents in each education category, and fill out the table.
Grade School Education High School Education College Education All Adults
% for withdrawl 73%
% against withdrawl 27%
Total 100% 100% 100% 100%
Why did you guess the numbers you did?
2) *Note: The title of this discussion topic comes from a quote often attributed to former British Prime Minister Benjamin Disraeli, who claimed that there are three types of lies: "Lies, Damned Lies, and Statistics"
The University of South Central Maryland (USCM) is being sued for sexually discriminatory hiring practices. Several years ago, they hired two classes of employees, administrative staff and academic staff. They received 750 applications from women for administrative staff positions, of which they hired 250, and 250 applications from women for academic positions, of which they hired 200. In total, then, they had 1000 applications from women of which they hired 450, or 45%. They received 300 applications from men for the administrative positions, of which they hired 75, and 700 applications from men for the academic positions, of which they hired 550. In total, of the 1000 applications they received from men, they hired 625, or 62.5%.
Based on the numbers presented, what do you think of the discrimination claim (Hint: Review Simpson's Paradox).
3) Operations and production managers often use the normal distribution as a probability model to forecast demand in order to determine inventory levels; manage the supply chain; control production and service processes ; and perform quality assurance checks on products and services. The information gained from such statistical analyses help managers optimize resource allocation decisions and reduce process times, which in turn often improves contribution margins and customer satisfaction.
Based on your understanding of the characteristics of the normal distribution, examine the attached chart (assume that the process specifications have a low bound of 9 and an upper bound of 15), and contribute to our discussion by posting an response to ONE of the questions below, and by responding to a post of a classmate.
Does either of the processes fit a normal distribution? Why or why not?
Which processes shows more variation? What does that mean?
If the company specified tolerance limits of +/-3 standard deviations, which of the above processes more consistently meets specifics? Explain why.
If the company specified tolerance limits of +/-6 standard deviations (six sigma), are they loosening or tightening their quality standards?
Looking at the processes again, under Six Sigma, which is/are acceptable?