Data Classification Qualitative Data: attributes, labels, or non numerical entries. This is also called Categorical Data. Quantitative Data: numerical measurements or counts City Population Baltimore, MD 702,979 Boston, MA 547,725 Dallas, TX 1,022,830 Las Vegas, NV 327,878 Lincoln, NE 203,076 Seattle, WA 520,947 Quantitative Data Qualitative Data

Meaningful Calculations The level of measurement determines which statistical calculations are meaningful for that data. There are 4 levels of measurement. Level of Measurement Definition Example Meaningful Calculations Nominal (for qualitative data only) Used with data where no math calculations can be made…only categorizing and labeling (LIST) Major PGA Tournaments - Put in a category Ordinal (for qualitative or quantitative data) Used for data that can be arranged in order, but differences between data entries cannot be calculated Motion Picture Association of America Rating Descriptions Put in a category Arrange in order

Meaningful Calculations Level of Measurement Definition Example Meaningful Calculations Interval (for quantitative data) Used with data that can be arranged in order and can calculate differences in data entries. Data entry of 0 is an actual value. Average Monthly Temperature for Sacramento, CA Years / Time Put in a category Arrange in order Find differences in values Ratio Same as interval level, but can calculate proportions or percents for comparison. Data entry of 0 means none. Average Monthly Precipitation for Sacramento, CA Find ratios of values

Identify each data set’s level of measurement. Nominal 1) A collection of phone numbers 2) The heart rate, in beats per minute, of an athlete who is exercising. Ratio 3) The body temperature (OF) of an athlete who is exercising Interval Ordinal 4) The final standings of the Northeast Division of the NHL

Practice Problems Pg 12 – 13 # 7 – 20 all