Paper, Order, or Assignment Requirements
We will address the following topics:
• Measures of Central Tendency (mean, median, mode, midrange, 50th percentile)
• Measures of Variability or Dispersion (range, variance, standard deviation, percentiles)
• Five Number Summary and Boxplot
After we collect data, we need to make sense of the information. One way to do this is to organize the data by finding the center and spread. If we want to compare the ages of people who live in Los Angeles with those who live in Newport Beach, we may want to compare their mean, median, and mode. In looking up this information, we see that the mean or average age is higher in Newport Beach. We might consider various reasons why this is true. However, when considering the center of the home prices in Newport Beach, we may not want to use the mean, because the very expensive homes throw all of the data off; the data are sensitive to extreme scores. Thus, the “center” of the home prices is generally given as a median or the middle number.
We want to have a basis for comparison. Which is bigger or smaller? Which has a larger or smaller range of scores? When the distribution is skewed or asymmetrically clumped, the mean, median, and mode are quite different. If four home prices are 60,000, 70,000, 80,000, and 90,000. Then the mean (average) and median (middle number) are both the same, 75,000. However, now imagine that a neighbor takes three plots of land on the nearby hill overlooking the water and builds a mega-home worth 2,000,000. The mean home price is now $460,000, but the new median is 80,000. Which value better reflects the cost of these homes?
This week we will consider when to use the various measurements for central tendency and variability and which measurements are best to use in each case.
Center and Spread of the Quantitative Data – Collect twenty (20) pieces of quantitative data and find the mean, variance, standard deviation, and five number summary. Explain the importance of this data, what you find interesting about the data, and why the public should know. The question is asked, “On the average, how many hours are you on the computer each week?” Describe the population and sample. Then graph the data (dotplot, stemplot, histogram, frequency polygon, scatterplot, time series graph, pie graph, and Pareto chart).
Note: A website, infographic, or other outside reference is required
Required Text: Triola, M. F., Triola, M. F., & Humphrey, P. (2012). Elementary statistics with technology update. Boston, MA: Pearson Learning Solutions.
Hardback – Triola 12 th Edition Elementary Statistics w/ MyMathLab ISBN-13: 978-0321890238 ISBN-10: 032189023X
“Loose Leaf” version–30% less expensive, also with the required MyMathLab access ISBN: 0321869478