LSP 120: Quantitative Reasoning and Technological Literacy Topic 1: Introduction to Quantitative Reasoning and Linear Models Prepared by Ozlem Elgun1

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Why are we here? Data: numbers with a context Cell: each data point is recorded in a cell Observation: each row of cells form an observation for a subject/individual Variable: any characteristic of an individual Prepared by Ozlem Elgun3

Why Data? 1) Data beat anecdotes “Belief is no substitute for arithmetic.” Henry Spencer Data are more reliable than anecdotes, because they systematically describe an overall picture rather than focus on a few incidents. Prepared by Ozlem Elgun4

Why Data? 2. Where the data come from is important. “Figures won’t lie, but liars will figure.” Gen. Charles H. Grosvenor ( ), Ohio Rep. Prepared by Ozlem Elgun5

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Familiarizing with Data Open Excel Collect data: – Ask 5 classmates the approximate # of text messages they send per day – Record the data on Excel spreadsheet Calculate average using the Average function on Excel. (There are many functions such as sum, count, slope, intercept etc. that we will use in this class) Prepared by Ozlem Elgun7

What is a linear function? Most people would say it is a straight line or that it fits the equation y = mx + b. They are correct, but what is true about a function that when graphed yields a straight line? What is the relationship between the variables in a linear function? A linear function indicates a relationship between x and y that has a fixed or constant rate of change. Prepared by Ozlem Elgun8

Is the relationship between x and y is linear? The first thing we want to do is be able to determine whether a table of values for 2 variables represents a linear function. In order to do that we use the formula below: Prepared by Ozlem Elgun9

To be continued…. Prepared by Ozlem Elgun10