1. Plotting in Excel KY
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2. Plotting in Excel Select Insert from the main menu
Select All Chart Types
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3. Column Chart
Definition: A chart that consists of multiple columns (vertical bars), and the height of each column represents the quantity associated with the corresponding category.
Use this type of chart for visual comparison of the quantities associated with different categories
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4. Column Chart - Example Select Insert → Column Chart → 2D Column
Select data range
Category
No. of Student
Frosh
4000
Sophomore
3500
Junior
6800
Senior
7000
Graduate
8000
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5. Column Chart - Example Chart Layout options
Select the option with Chart Title and Axes Title
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6. Column Chart - Example
Edit the chart and axes titles, place the curser on the text and right click
A plot must have a title and a description of the axes, including units if applicable
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7. Multi-Column Chart - Example
Grade
2001
2007
Frosh
3500
4000
Sophomore
3000
Junior
6250
6800
Senior
6750
7000
Grad.
7250
8000
Multiple Column Charts are used for Comparison, select all three columns. Include title, description for axes and modify the legends.
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Engineering 10

8. Pie Chart
Definition: A graph in the shape of a circle divided into sectors, whose areas correspond to the proportions of the quantities.
Application: Visual representation of relative magnitudes of a given set of quantities
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9. Pie Chart Label the Chart Use Chart Layout Engineering 10
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10. XY (Scatter) Plots
XY plots are two dimensional graphs. Scientifically, it is a plot of independent variable (x) against a dependent variable (y).
The plot is used to obtain a functional relationship between two variables
There are five options in Chart sub-type menu. The first option, where only points are plotted, is the most common type used in engineering and science fields. A curve is fitted to the plotted points to obtain the function describing the relationship between the two variable.
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11. XY (Scatter) Plots - Example
Select Chart Layout (Layout 1)
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12. Fitting a Curve to Data Points (XY)
Given the plot of test results, the question is what would be your test score if you studied for 2.5 hours, no data is available for 2.5 hours.
In order to answer the question, you have to find the equation relating the test score to the number of hours spent studying.
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13. Fitting a Curve to Data Points (XY)
Engineers frequently collect paired data in order to understand the characteristics or behavior of an object or a system.
The goal is to capture the overall trend reflected by the entire data set. This can be achieved by obtaining the equation of a curve (or a straight line) that best describes (fits) the data points. The Method of Least Squares is used for this purpose.
The Method of Least Squares minimizes the sum of the squares of the errors.
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14. Fitting a Curve to Data Points (XY)
The Method of Least Squares can be used to fit many different types of functions through a set of data points. The data obtained in many engineering applications may be represented by a straight line, exponential function, a power function, or a polynomial.
Equation Type
Mathematical expression
y = ax + b
Linear (straight line)
Exponential
y = aebx
Power
y = axb
Logarithmic
y = a ln(x) + b
Polynomial (up to 6th order)
y = c1 + c2x + c3x2 + …… + ck+1xk
In Excel k = 6
The Method of Least Squares obtains the appropriate set of values for the coefficients, a, b, c1, ….
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15. Fitting a Curve to Data Points (XY)
Select a data point and right click, then choose Add Trendline option. Select the curve to fit the data.
Data point
Check the Set Intercept box to force the curve to pass through origin (0,0).
Check the Display Equation on chart and the Display R-squared value on chart boxes.
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16. Fitting the best Curve to Data Points
There are six option to select from, start with your best guess and check the fit. The best fit is indicated by how close the correlation factor, R2, is to unity, the closer to 1 the better the fit.
Exponential
Linear
Polynomial (3rd order)
Polynomial (5th order)
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17. Fitting the best Curve to Data Points
Given the plot of test results, the question is what would be your test score if you studied for 2.5 hours, no data is available for 2.5 hours.
y = .2361(2.5)5 – (2.5) (2.5)3 – (2.5) (2.5) – 60
y = (exam score for 2.5 hours of studying)
Substitute x = 2.5 in the 5th order polynomial equation to find y (hours spent studying).
Linear
Exponential
Polynomial (3rd order)
Polynomial (5th order)
Equation Type
Exam Score
R-squared value
.73
.675
.913
.931
75.1
77.3
62.9
65.5
Best fit (does not make sense)
Best answer
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Engineering 10

18. An engineer is responsible for monitoring the quality of 1000-ohm resistors. To do this, the engineer must measure the resistance of a number of resistors within a batch selected at random. The results are shown below. The acceptable variation is ± 2% ( ). The question is how many resistors fall within the acceptable range.
Sample No Resistance, ohm Sample No Resistance, ohm
Histogram
There are times that it is desirable to plot the data in a manner that shows how the values are distributed within a certain range. This type of plot is called a histogram (a relative frequency plot).
Largest value = 1045
Smallest value = 935
Use the Max and MIN functions to find:
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19. Histogram
Data menu
If Data Analysis (or Solver) does not appear, select File and choose Options, select Add-Ins, click on Go and check the boxes for Analysis ToolPak and Solver
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20. Histogram Create the Bin range
To create a histogram, you must first subdivide the range of the data into equally spaced intervals. The first interval must start at or below the smallest data value, and the last interval must extend to or beyond the largest data value. The interval bounds is called the Bin Range in Excel.
Largest value = 1045
Smallest value = 935
The acceptable variation is ± 2% (980 to1020).
Create the Bin range
Find the desired interval: 40 ( =40)
The Bin Range
980
1020
900
< 935
Create a column in the Excel for the Bin Range
940
1060
> 1045
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21. Histogram Data range (has to be in one column)
Select Data Analysis and choose Histogram
Bin range
Select to obtain a histogram plot
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22. Histogram 16 data values fall in the 980+ – 1020 range
The rule used in Excel is that if a data value falls on the interval boundary, the data value is assigned to the lower interval
So, if you buy a resistor from this manufacturer there is only a (16/30)100 = 53.3% chance that resistor has a value of 1000±2%
San Jose State University
Engineering 10