1. Warm Up
A 2005 study took a random sample of scientists in the natural sciences and a separate random sample of scientists in the social sciences. Each was asked to rate his/her level of spirituality. The data is below. Very Moderate Slight Not at all Natural Sciences Social Sciences Is there evidence that the spirituality category proportions are not the same for natural and social sciences scientists?

2. Example
A random survey of stroke victims investigated if there is an association between education level and stroke survival rates. < High School High School College Grad Sch. Died Survived

3. Practice
In a 2007 study, the number of premature vs. full term babies was compared for babies conceived naturally and using Assisted Reproduction Technology. The data comes from a random sample of 21,614 births. ART Natural Premature Full Term ,843 1)Is there convincing evidence of an association between the use of ART and premature birth rates? Use alpha of 0.01.