Range is the
simplest way to calculate the spread of a distribution. It is also
extremely influenced by outliers.
calculating the standard deviation, calculate the variance. Make
sure whether you need to find the population variance and standard
deviation or a sample variance or standard deviation.
calculating the interquartile range, make sure that the data are
ordered from lowest to highest.
deviation is the best measure of spreads since it uses all of the
observations; however, if the data are skewed, the interquartile
range is the preferred measure of the center.
Measuring Spread: Range, IQR, Standard Deviation
Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.
The book and CD package includes five full length practice exams in addition to a full 15 chapters of review that is divided into the four major themes on the statistics test: Exploratory Analysis, Planning a Study, Probability, and Statistical Interference.
The book includes 2 full length practice tests with detailed answers and explanations, a full review of the subject material presented, and step-by-step techniques for cracking each type of statistical analysis question.