# Probability and Statistics for Engineering and the Sciences (with Student Suite Online)

• Notes
• PresidentHackerCaribou10582
• 12

This preview shows pages 1–7. Sign up to view the full content.

Stat 321 – Day 3 Measures of Spread

This preview has intentionally blurred sections. Sign up to view the full version.

Announcements Lab questions? NHL: \$209.78 MLB: \$147.72 NFL: \$322.82 NBA: \$244.48 HW 1 (due Tuesday) questions? Reminder: Office Hour today 1-3
Last Time – Measures of Center Mean = average all values But watch for outliers (not resistant) Median = “middle” observation “Typical” value Notes: “mode” usually not so useful with quantitative data Center may not be most relevant to study question Percentile = value with p% of data below it Median = 50 th percentile Lower fourth = 25 th percentile

This preview has intentionally blurred sections. Sign up to view the full version.

Last Time – “Test” for outliers 1.5f s criterion Any values more than 1.5 f s beyond lower fourth or upper fourth is flagged “Extreme” outlier if more than 3 f s away Modified boxplot
Old Faithful inter-eruption time

This preview has intentionally blurred sections. Sign up to view the full version.

Example 1: Hypothetical Quiz  Scores Predictions Find the fourth spread for each class Median = 15 th observation = 5 points Lower fourth = median of bottom 15 observations = 8 th observation = 2 Upper fourth = 8 Fourth spread = 6
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern