EC255 Chapter Notes - Chapter 2: Cumulative Frequency Analysis, Frequency Distribution, Railways Act 1921
Document Summary
Ungrouped data: not aggregated/not summarized; also called raw data. Grouped data: aggregated data; already organized into frequency distribution; already organized into histogram. Frequency distribution: list or table containing the values of a variable (or a set of ranges within which the data fall) and the corresponding frequencies with which each value occurs (or frequencies with which data fall within each range) Summarize data to make it useful for interpretation. An advertiser asks 200 customers how many days per week they read the daily newspaper. Your manager asks you to collect and analyze the daily demand for ynox xd fertilizer (in lbs. ) in the kw area during the period sept 1, 2013 aug. 31, 2014. Continuous ratio data: possible values are not countable. Sort from low to high (only if you"re doing this by hand) Find range 19 2 = 17 lbs. Select number of classes: 10 (usually between 5 and 20) Compute class width: 2 (17/10 then round up)
