Microsoft Excel 2003 Data Analysis

Click on the Payment Table worksheet tab Let’s enter the input values for the function first and then create the function.. Click on the Expand dialog box button The Nper argument box w

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Microsoft Excel 2003

Data Analysis

Larry F Vint, Ph.D

lvint@niu.edu

815-753-8053

Technical Advisory Group Customer Support Services Northern Illinois University

120 Swen Parson Hall DeKalb, IL 60115

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Microsoft Excel 2003 Data Analysis

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Using Excel’s Data Analysis Tools

Excel includes a number of add-in tools to assist with a number of data handling,

reporting and analysis functions

1 Click on the worksheet tab labeled Data Analysis

2 Click on the Tools pull-down menus

3 Click on Add-Ins

4 Check Analysis ToolPak as in Figure

DA-01

5 Also Check Solver as we will be

using the Solver in a later exercise

6 Click OK

This unpacks the chosen Excel Add-in tools

and makes them available for use If the

Add-in list is empty, there may have been a limited

installation of MS Office If this is the case,

the MS Office CDs will be needed to install

these Add-in tools

7 Click on the Tools pull-down menus

The Descriptive Statistics

box is shown in Figure DA-03

Figure DA-01

Figure DA-02

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11 Click on the contract button for the Input Range box

12 Highlight B1 through C7

13 Click the expand button

14 Check the Labels in First Row box

15 Click on the contract button for the Output Range box

16 Click on cell A11

18 Check the Summary

Statistics box

The Descriptive Statistics window

should now look like Figure DA-04

19 Click OK

20 The output will be

crowded so highlight the

column headings for

columns A through D

21 Position the cursor over

the right-hand border of

one of the highlighted

columns and double-click

to increase the width of

each column to the widest cell in the column

The resulting Descriptive Statistics should look like Figure DA-05

Figure DA-05

Figure DA-04

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Let’s try another analysis Regression statistics can be useful in evaluating past

trends and predicting future consequences Using the data in the Data Analysis

worksheet, let’s compute the regression of Expenditure increases as a function of

the number of Students

22 Click on the Tools pull-down menus again

23 Click on Data Analysis

24 Select Regression from the Analysis Tools

25 Click OK

26 Click on the contract button for the Input Y Range box

27 Highlight B1 through B7

29 Click on the contract button for the Input X Range box

30 Highlight C1 through C7

32 Check the Labels box

33 Click on the contract button for the Output Range box

34 Click on cell E1

The Regression window should now look like Figure DA-06

36 Click OK

37 The output will be

crowded so highlight the

column headings for

columns E through M

38 Position the cursor over

the right-hand border of

one of the highlighted

columns and double-click

to increase the width of

each column to the

widest cell in the column

The resulting Regression

Statistics should look like

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The coefficient for STUDENTS, 5069.547647, indicates that every student adds

$5,069.55 to EXPENDITURES and that even with no students there would be

$12,763.11 in EXPENDITURES Let’s use these coefficients to set up an

equation to predict EXPENDITURES based upon student numbers

These steps have created a prediction equation based upon the regression

analysis that can be used to predict expenditures for varying numbers of

students Care must be taken in interpreting results greatly beyond the range of

existing data; i.e the prediction may be reasonable for 20 students, but not

realistic for 100 students

47 Click on cell O3

48 Type 20

49 Press Enter

The equation predicts that if we had 20 students we could expect expenditures to be $114,

154.06 The above examples illustrate some of the types of statistical analysis that can be

performed with Excel’s Add-in Analysis ToolPak

Figure DA-07

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Most people familiar with databases will mistakenly assume the Tables feature in

Excel is used similarly but they are mistaken The Tables feature in Excel is

another What-If analysis tool that displays the result of a formula with different

sets of input values

For this example we will create a formula that determines the monthly payments

for the principal of an investment given a fixed interest rate We will use the

PPMT function that is one of the financial functions provided by Excel to calculate

the monthly payments to be made on an investment over a specified period of

time We will enter the interest rate,

Let’s first go to the Payment Table worksheet for the function and ensuing table

1 Click on the Payment Table worksheet tab

Let’s enter the input values for the function first and then create the function

These three values will be used by the PMT function to calculate the monthly

payments Let’s enter the formula

8 Click on cell B6

9 Click on the Paste Function toolbar button

10 From popup Insert Function window click on the Financial category

from the select a category pick

list

11 Scroll down the list box labeled

Select a function until you see

the PMT function and click on it

as in Figure PT-01

12 Click on the OK button

The formula box appears listing the

arguments needed by the PMT function

The three required arguments, Rate,

Nper, and Pv, are indicated in boldface

Two optional arguments are Fv and

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13 To better understand the arguments needed for the PMT function click

on Help on this function

We can now see that Fv and Type are the future value and payment method,

respectively The future value is the balanced desired after the last payment was

made If no argument is supplied to this argument the default is zero The Type

argument is used to indicate when the payment is made A value of True

indicates the payment is made at the beginning of the period and a value of

False or if this value is not supplied the payment is made at the end of the period

We will supply the three required arguments since we want to attain a zero

balance after all payments are made and the payments are made at the end of

each pay period

14 Click within the box labeled Rate

15 Type (B1/12)/100

Cell B1 contains the annual interest rate Since we wish to determine the

monthly payments we must express on all arguments in monthly units So

dividing the annual rage by 12 months will give us the monthly interest rate We

then divided the monthly interest rate by 100 to express on the percentage as a

decimal number

16 Click within the box labeled Nper

17 Click on the Contract dialog box button to the right of this box

The formula box will be temporarily suppressed and the box containing the Nper

argument is displayed Whenever we click on a cell Excel will fill the cell address

into the Nper argument box

18 Click on cell B2

The cell address B2 is placed within the Nper argument box

19 Click on the Expand dialog box button

The Nper argument box will contain the cell address B2 that contains the pay

period that is expressed in years Just like the Rate argument we must express

the Nper argument in months So we must multiply the contents of cell B2 by 12

20 Click on the End key to

move the insertion point

to the end of the

argument

21 Type *12

The Nper argument should now

read B2*12

22 Click within the box

labeled Pv and click on

the Contract button

Figure PT-02

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23 Click on cell B3 and then click on the Expand dialog box button

The Pv argument is the principal value We will not supply any arguments for the

Fv and Type arguments because we want the future value of this investment to

equal zero when the pay period ends and we are paying at the end of each

month, which are the defaults when an argument is not supplied Figure 4 shows

the formula box now Compare your formula box to the figure and correct any

mistakes The value of each argument is evaluated and displayed to the right of

the argument boxes The monthly interest rate, which is expressed as a decimal

value, is 00625 The number of periods is 60 months and the principal value is

18000

24 Click OK

A negative value of $360.68 is displayed in cell B6 The payment is negative

because it is the amount we must pay each month to pay off an $18,000

investment at 7.5% for 5 years

Suppose you want to see how the monthly payments will change when the

annual interest rate and pay period are modified We can set up a table to

perform this what-if analysis The table will display the input parameters along

the top row and left-most column with each cell within the table displaying the

formula result for each combination of input values

To set up the table, the formula must be in the top, leftmost column Then the

input values are entered on the same row beginning in the next cell to the right of

the formula and on the same column beginning with the next cell below the

The cell range B7:B9 should be highlighted

27 Type 3 and press Enter

We will use the leftmost column to supply different number of pay period values

to the PMT function

30 Now position the cursor on cell C6 then continuously hold the left mouse

button down

31 Drag the mouse pointer to cell D6 and then release the mouse button

The cell range C6:D6 should be highlighted

33 Type 6.5 and click on the fill handle of the highlighted range C6:D6

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34 Continuously holding down on the left mouse button, drag the fill handle

to column K, until the number 10 appears, and release the mouse button

We allowed Excel to use the pattern of 0.5 percent increases to set up a list of

interest rates from six to ten in 0.5 increments Now we can use row six to

supply these different interest rate values to the PMT function Figure PT-03

shows the column and row input values for this table along with the function To

set up the What-if table showing what payments would be across this range of

payment periods and interest rates:

35 Position the cursor on cell B6 and hold the left mouse button down

36 Drag the mouse pointer to cell K9 and release the mouse button

The cell range B6:K9 should be highlighted and if is not then repeat steps 35 and

36 above You must highlight the entire cell range that will display the results of

the table and the formula must be in the top, leftmost cell of the table

37 Click on Data in the dropdown menus

38 Click on Table

A dialog box entitled Table appears with two options labeled Row input cell and

Column input cell We must specify the cell range containing the row input

values within the table and the cell range containing the column input values

39 Click within the box labeled Row input cell

40 Click on the Contract button

The cell address $B$1 should be filled into the Row input cell box Cell B1

contains the annual interest rate and the table will replace the interest rate using

the five values entered in cells C6, D6, E6, F6, and G6

42 Click on the Expand button to return to the Table dialog box

43 Click within the Column input cell box

44 Click on the Contract button

Figure PT-03

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The cell address $B$2 is filled into the Column input cell box Cell B2 contains

the number of periods and Excel will use the values supplied in cells B7, B8, and

B9 to for the number of periods

46 Click on the Expand button to return to the Table dialog box

47 Click on the OK button

The table should result like Figure PT-04 Cell F9 displays the result of the PMT

function using an annual interest rate of 7.5% and a pay period of 5 years

This is the same result as cell B6 because these were the original values

supplied to the function Now you can compare the different payment values

across different interest rates and pay periods For example, cell E7 shows the

monthly payment amount if the interest rate is 7% and the pay period is only 3

years Cell G8 shows the monthly payment amount if the interest rate is 8% and

the pay period is 4 years The formatting of the monthly payments in the newly

created table can be easily set using the Format Painter

49 Click on the Format Painter

50 Swipe the Format Painter across cells C7 through K9

The table will now look like Figure PT-05

Figure PT-04

Figure PT-05

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Evaluating Trends

Excel has a number of tools to assist in analyzing trends in data Trend analysis

can be utilized to predict future results In this section we will use Excel’s

Trendline tool to analyze several possible trends in a department’s tuition

income We will then utilize Excel’s Linear and Growth Trend tools to predict

future tuition income based upon past results

1 Click on the Trends worksheet tab

A chart has been created from the data range B7:C11 We will add a series of

trendlines to this chart and evaluate how well they describe the existing data

2 Right-click on one of the blue columns representing a data point in the

chart

3 Click on Add Trendline from the popup menu as shown in Figure ET-01

Figure ET-02 shows the types of

trendlines that can be to the chart

Excel offers six choices of types

of trendlines that might be applied

to charted data We will examine

visually how well each fits the

data We will also display the

statistical formulas Excel has

computed to calculate data points

on the trendline and the R2 values

which statistically represent how

well the trendline formula

describes the data

4 Click on the Linear box

as in Figure ET-02

Figure ET-01

Figure ET-02

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Figure TL6

5 Click OK

A linear trendline has been applied to the chart

6 Right-click on the trendline The menu that pops up will allow you to

either Format trendline or Clear the trendline

7 Click on Format Trendline

The Format Trendline window that pops up has three tabs The first, Patterns,

will allow you to change the line style, color and weight of the trendline The

second, Type, will allow you to change the type of trendline being established

8 Click on the third, the Options tab

The Options window in Figure ET-03

will allow us to apply a custom

trendline name, forcast forward or

backward, reset the intercept on the

y-axis, display the trendline equation

on the chart and display the

R-squared value on the chart:

9 Check the Display equation

then check the Display

R-squared value boxes

10 Click OK

The formula y = 146.88x + 231.68

and R2 = 0.9831 appears above the

trendline (Figure ET-04) This is the

linear regression formula Excel has

calculated to describe the tuition

income data The R2 value is

the percent of variation in the

data that is described by the

regression equation A value of

1.0 means the equation can

completely account for variation

in the data The smaller the R2

value the less useful the

equation is in describing the

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