{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

ams 102 chapter 5

# ams 102 chapter 5 - Chapter 5 Summarizing Data Numerically...

This preview shows pages 1–3. Sign up to view the full content.

Page 1 of 5 Chapter 5: Summarizing Data Numerically Measures of center - mean - median - mode (mainly for qualitative data) The average or mean is a measure of center (middle of a set of data) If our data is a sample, then the mean is a statistic x (pronounced “x-bar”) If our data is a population, then the mean is a parameter (pronounced “mu”) mean = sum of observation values divided by the # of total observations sample mean: 1 1 2 ... n i i n x x x x x n n = + + + = = ° Ex. 1 What’s average amount of time to finish a 5K race? Sample of 5 participants (times rounded to nearest minute) 45 53 45 50 48 Ex. 2 Let’s Do It! 5.2 We have 7 students. The mean score for 3 of these students is 54 and the mean score for the other 4 students is 76. What is the mean score for all seven students? Ex. 3 What happens if the last number in Ex. 1 was an 80 instead of 48? Find the new mean 45 53 45 50 80 The mean is influenced by extreme values – we won’t get an accurate value for where the middle of the data is. For skewed distributions (extreme values present) the median is a better measure of center. median – value that cuts the ordered data into ½. The median is resistant to extreme values Finding the median 1. Arrange the observations in increasing order 2. If the # of observations is odd, the median is the value at the 1 2 n + th location

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

View Full Document
Page 2 of 5 If the # of observations is even, the median is the average of the values at the 2 n th and 1 2 n ± ² + ³ ´ µ th location Ex. 4 Find median of following values: 45 53 45 50 48 Ex. 5 Find median of following values: 45 53 45 50 48 55
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