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.

4. Is there a difference in doing a word search right-side up vs
Is there a difference in doing a word search right-side up vs. upside down?
Everyone will be given a word search puzzle. You will be randomly assigned to find the words by working either “right-side up” or “upside down.” You will have 7 minutes to find as many words as possible on the word search. We will construct a test of significance to see if there is a difference in the proportion of students that are successful at the word search between the 2 populations.

5. Is there a difference in doing a word search right-side up vs
Is there a difference in doing a word search right-side up vs. upside down?
1) Make a two-way table from the class data. 2) Using the class data, construct a significance test to determine if we have statistically significant evidence that the proportion of students that are successful at the word search is different if they work right-side up vs. upside down.