MATH 140 Lecture 1: 1.2-1.3
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Two different types of variables: numerical/quantitative variables (ex. hours, salary, gpa, categorical variables (ex. Sample: a small portion of the population: a single class of freshman from csun. Population: the whole group: ex: the whole student body of csun freshman. Categorical variables are usually coded which means they label them with numbers: ex: psychology= 0, english= 1, history= 2. Two different formats of data: stacked: each row represents one person, entries in row are related. 3. 2: unstacked: row entries aren"t related, each cell represents one person. Always round up to at least 4 decimal spaces in her class. 1. 3 organizing categorical data: ex: 0. 0578910293, round: 0. 058 no 0. 0579 or 0. 05789 ok. Frequency: the count of how many times something may occur: ex: how many students that study on campus/ how many students work outside of school. Formula for proportion (cid:1842)(cid:1867)(cid:1868)(cid:1867)(cid:1872)(cid:1867)(cid:1866)=(cid:1842)(cid:1872) (cid:1867)(cid:1858) (cid:1842)(cid:1867)(cid:1868)(cid:1873)(cid:1872)(cid:1867)(cid:1866) (cid:1841)(cid:1874)(cid:1857) (cid:1842)(cid:1867)(cid:1868)(cid:1873)(cid:1872)(cid:1867)(cid:1866)
