Week 11 Flashcards
Although common knowledge, how do you add a trendline to an excel graph? How do you display the equation of the line?
After plotting data…
- right click on a point and select “Add Trendline”
- Select “linear” curve, or whatever you need
- reformat the style of graph and stuff if needed
To display the line, click the line to format and then select “Display Equation on Chart”
What does the coefficient of Determination measure (R^2)? What do the values mean?
The Coefficient of Determination measures how closely data matches the best fit line!
It consists of a value from 0 to 1.
What do the values mean? Well:
- A value of 1 means that the output (y usually) can be predicted perfectly without error, for a given input x.
- A value of 0 means that it is not possible to predict y from x (no correlation!)
How would you set the y-intercept of a graph?
The default is 0, but you can change it to whatever you want by right clicking the line, scrolling down in the “Format Trendline” section, tick a box that says “set Intercept?” and then set the value!
Is it possible for a graph’s y value to be 1 if there’s 2 points? 3 points? How?
If you have a line with 2 points, you can get a R value of 1 always
If you have a binomial and 3 points, you can always get a R value of 1
etc.
If you change a linear fit to a polynomial fit, how do you expect the r^2 value to react?
If you specify the y-int, how will you expect the r^2 value to react?
Going from a linear fit to a polynomial fit gives one more parameter that can be adjusted to better fit the data, so r^2 WILL INCREASE!
If you specify the y-int, the r^2 value should decrease!
Which components (filters and UV) are you required to have in your system?
you need at least the 1 micron filter an the UV light! The 5 and 200 micron filters are optional, though they have their up and downsides.
What are the 7 attributes for the third module’s project?
Consumption (C)
Relative Cost (c_r)
Health and environmental risk exposure (E)
Power system greenhouse gas emissions (G)
Maintenance Occurences (M)
On Demand flow rate (Q_0)
Reliability (days consumption met) (R)
How do you calculate the net value of C_f, which is the coefficient for calculating filter pressure?
You just add all the C_f values from all the individual filters that you use!
What are we imagining that the consumers do if we do not meet their daily water needs for a day?
Also, how do you determine the consumption value (C) for the project?
We have to assume that they pay for 50L of water shipped in. This will result in a lower reliability score
Also, we have to determine the consumption value. We essentially create a target for ourselves to hit.
