Microsoft Excel Chapters 6&7 Nagendra Vemulapalli Nagendra.vemulapalli@mail.wvu.edu

Announcements Lesson B in MyITLab is due today (09/17/2012) by 11:59pm Homework Assignment2 is due on 09/21/2012 by 11:59pm Homework Assignment3 is due on 09/28/2012 by 11:59pm

Trend lines A trend line is Excel’s best guess at a mathematical equation to represent the given data We can then use that equation to predict the future. The possible types of trend lines are: Exponential Linear Log Polynomial Power 12/9/2018 Nagendra Vemulapalli

Adding the Trend Lines Select the series you want to add the trend line to. Right click and choose Add Trend line Select the Trend line that “Best Fits” the Data points Turn on “Display R-squared value on chart” R-squared value: “Close to 1.0” means better approximation Note that the R-squared value does not always give you the best result. Think in all perspectives 12/9/2018 Nagendra Vemulapalli

Alligator Example Download example1 file We will add a Trend line “Line of Best Fit” will be identified for a scattered plot: We will fit a line on the data points and figure out which type of line will be the best model for the data Exponential Linear Log Polynomial Power 12/9/2018 Nagendra Vemulapalli

Alligator Example Cont’d – Scatter Chart Select the range A5:B29 Creating the scatter chart: Insert ribbon Scatter 12/9/2018 Nagendra Vemulapalli

Scatter Chart Labeling the chart Design tab Chart Layouts drop down menu Select the first one that has labels for the title, x-axis, and y-axis Type the following: Chart Title: Alligator Regression X Axis Title  Length in Inches Y Axis Title  Weight in Pounds 12/9/2018 Nagendra Vemulapalli

Adding a Trendline Cont’d Remember that we want to examine the line that best fits our points Exponential Fits nicely around the data points Exponential Curve that touches all of them and follows the direction of points Nagendra Vemulapalli 12/9/2018Date

Adding a Trendline Cont’d Linear A straight line Goes in the same direction but does not touch most of the points! Therefore, it’s probably not the best one to use as our model Nagendra Vemulapalli 12/9/2018

Adding a Trendline Cont’d Logarithmic It does not seem to model our scattered data points accurately Nagendra Vemulapalli 12/9/2018

Adding a Trendline Cont’d Polynomial Most of the points are touched Moving in the same direction of the data Similar to the exponential Nagendra Vemulapalli 12/9/2018

Adding a Trendline Cont’d Power Moves in the same direction of the data, but doesn’t touch most of the points Nagendra Vemulapalli 12/9/2018

Adding a Trendline Cont’d Narrow and compare our options Exponential “looks” better choice but wait try increasing order of polynomial to 3! Exponential vs. Polynomial Nagendra Vemulapalli 12/9/2018

Predicting Predicting graphically Predict Numerically Compare Results Forecast forward Predict Numerically Display equation Increase precision Reformat Equation Insert into dataset Compare Results

Predicting Graphically Click on your Trendline to highlight it Right click Select “Format Trendline…”

Forecasting forward

Forecasting forward Enter 3.0 Close Chart is extended to almost 150 inches and almost 700 pounds (visually)

Predicting Numerically More exact numbers to base our future estimates on Displaying an equation on the chart Right click on the Trendline Select “Format Trendline…”

Predicting Numerically Check the box to the left of “Display Equation on chart” The equation will be displayed on your chart Increasing precision Right click on the equation “Format Trendline Label…” “Number” Decimal Places: 4 Close Precision has increasing

Reformatting equation Now we know the equation of the curve y = 0.0008x3 - 0.1542x2 + 11.4730x - 277.8223 Let’s convert this into a formula in Excel. In cell B30, enter =0.0008*A30^3-0.1542*A30^2+11.473*A30-277.8223 Note that ‘*’ is a multiplication and ‘^’ is a power. Autofill B31 and B32 and you can predict the unknown values.

Sorting Excel allows you to sort a spreadsheet by alphabetical or numerical or chronological order. The order Can be either Ascending or Descending

Sorting Example Download the example2 file from Today lecture notes Select A2:D10 Data ribbon -> Sort & Filter group -> Sort button To sort ascending on last name, choose Sort by “Last”

Sorting Example Continued Multiple sorting can be done based on other additional criteria as well. Select A2:D10 Sort button from Data ribbon Click Add Level button To do the additional ascending sort “First Name” choose Then by “First”

=AVERAGE(’Employee Info’!D2:D10) Sheet References You can reference data from another sheet just like you can reference data from your current sheet. Flip to the Salary Stats sheet in Example2 file In cell B1 type =AVERAGE( For entering the Range Switch to the Employee Info sheet and select D2:D10 and hit enter while you are on the same sheet Then cell B1 in Salary Stats sheet should become =AVERAGE(’Employee Info’!D2:D10) Repeat the same process for Total Salaries

Sheet Referencing.. Calculate the salary Ratio of the Employee in 3rd row to Employee in the 2nd row. It should look like ='Employee Info'!D3/'Employee Info'!D2

Freezing/Unfreezing Top Row Freezing can keep part of a sheet in place while allowing another to scroll. To Freeze the top row: View ribbon -> Window group -> Freeze Panes -> Freeze Top Row Scroll down and observe! To Unfreeze: View ribbon -> Window group -> Freeze Panes -> Unfreeze

Hide/Unhide cells To hide Rows 2 to4 To unhide rows 2 to 4 In Employee Info sheet, select rows from 2 to 4 Right Click -> Select Hide To unhide rows 2 to 4 Select Row 1 and Row 5 Right Click -> Select Unhide You can apply the same technique to columns

Locking /Unlocking a worksheet If a worksheet is “protected” , meaning that the locking property is on, then all cells are locked and no data can be entered. Locking a worksheet Home ribbon -> Cells group -> Format Cells -> Protect sheet… Enter a password (twice) Click OK Unlocking Home ribbon -> Cells group -> Format Cells -> Unprotect sheet…