Emtech lesson 2

numbersright alignedType an apostrophe (') before the number ex. '2018How do you enter a number as a text?Type a mixed number. Use 0 if the fraction is less than 1.How do you enter a fraction without turning into a date?Formulas- equations that perform calculations in your spreadsheet - always begin with an equal sign (=)FunctionsExcel-defined formulascalculates mean=AVERAGE(first cell:last cell)calculates median=MEDIAN(first cell:last cell)- Data presented in tables or charts are easier to understand than raw data. - They save time and effort, and allow us to take a glimpse at the entire picture with one glanceWhy visualizing data?- Nominal - Ordinal - Interval - RatioWhat are the types of data? (NOIR)Nominalnames and labelsOrdinalranks and orderIntervaldata that can be represented as real numbersRatiodata that can be represented as real numbers, but have a real zero- Pie Chart - Bar Chart - Histogram - ScatterplotWhat ways can we visualize and represent data? (PBHS)if is nominal or ordinalWhen are the Pie and Bar Chart used?Scatterplot: in focus- Unique - Allows to represent two variables at the same time unlike other data representation techniques only allow us to describe one variable at a time. - also allow to see the relationship between two variablesDependent Variable- the variable whose value is dependent on, or assumed dependent on another variable. - label as variable "y". - placed along the y-axis in a scatterplotIndependent Variable- variable with whom the dependent variable is dependent on, or is assumed dependent on. - labeled as variable "x". - placed along the x- axis in a scatterplot- how well the different data points converge to form a line - We can estimate this by drawing a straight line through the points in such a way that THE LINE REPRESENTS THE RELATIONSHIPWhat is the linearity of a scatterplot?Linear Relationshiplooks like /Positive Linear RelationshipWhen one variable INCREASES, and the other variable also INCREASESNegative Linear RelationshipWhen the two variables tend to go in OPPOSITE DIRECTION (one INCREASING, the other DECREASING)linear relationshipTwo variables are correlated if there is a ___________ between themLeast-Squares CriterionThe sum of the squares of the vertical distances (d) from the data points to the line is made as small as possibleInterpolationestimation of a value BETWEEN TWO KNOWN VALUES in a given sequence or equationExtrapolation- estimation of a value that is not explicitly stated, or of a value that is NOT IN BETWEEN TWO KNOWN VALUES in a sequence or equation - far less reliable than interpolation