How is Excel used in Science? Today we'll learn
how to use Microsoft Excel in Science. Viscosity measurements of
polymer solutions, for example, help us to determine molecular weights
of the polymers in question. Here we have viscosity measurements of a
polymer solution at different concentrations using a viscometer. Now
let's see how we can create a graph and perform calculations on this
data to derive more information from our experiment.
- First we convert the viscosity measurements into
logarithmic values using the function '=ln(cell address containing the
number)
- Next we do an autofill to convert all the measurements into
the logarithmic values.
- Then we select the concentration values which will form the
x-axis of our graph, press 'ctrl' from the keyboard and select the
logarithmic values of the viscosity measurements which will form the
y-axis of our scattered xy-graph.
- We then click on the chart wizard, select the 'xy-scatter'
chart and press the button 'Press and hold to view sample'.
After clicking on next twice we assign the 'titles' to the x and y
axis.
- We place the created chart in sheet1 and edit it so that we
can view the details properly.
- We scale the x-axis appropriately as shown in the video.
- We then right-click on our data points in the chart and add
a trendline which shows how the values deviate from the 'exact'
straight line also called 'residuals'.
- We also add an equation on our chart by clicking on
'options' in the 'Add Trendline' window and check 'Display equation on
chart'. You can add other interesting information also.
- Next click in your measurement data area, select 'tools'
from the menu bar, select 'data analysis...' and finally 'regression'
- In the 'Regression' window you define the various input
data, confidence level,output range, residuals and residual plots by
checking the appropriate as shown in the training video.
- The statistical data and graph displayed by Excel gives the
user good information!
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