Ratio (quantitative) variables- also known as quantitative measures. Terms to know quantitative variable valid percent normal curve histogram skewness positive and negative skewness outlier mode, median, mean bimodal distribution variance, range, standard deviation, inter-quartile range percentile. Frequency distributions for rat vars: hard to use to find modes and medians. Reminder: note the difference between percent and valid percent : need it because we have to get to shape of the distribution, distribution shape is important because, normal curve, this is a bell-shaped curve. The graphic of a frequency distribution is called a histogram. Go to analyze and click on frequencies, put variable we want in box,(average percent mark), go to charts and click on histogram- click on show the normal curve - and delete the display frequency tables. Open data set: click on analyze on menu bar, choose descriptive statistics from dropdown menu, choose frequencies .