Linear regression How do I enter simple x and y data points to get a slope and intercept via: y = mx + b Every TI I've ever owned does it. Lost the manual. How do you do it on this model? Thanks, Bruce

The equation of any straight line, called a linear equation, can be written as: y = mx + b, where m is the slope of the line and b is the y-intercept. The y-intercept of this line is the value of y at the point where the line crosses the y axis.

Graphing Equations and Inequalities Slope and intercept First Glance

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gregg_27a4d257e54e7920

Use the statistics feature called linear regression to find the slope (m) and the intercept (b) then write the equation of the best line as y=mx+b

Your data must be in two lists L1 (for x-values), and L2 (for y-values). This is the default setting. Open the STAT utility, go to the regression models. Select your model then press ENTER. The command echoes on the main screen. For example let the regression be something called LinReg.
On the main screen you see LinReg
Complete the command line as follows
LinReg L1, L2, Y1, ENTER
You see the statistics including the regression equation.
If you go to Y= Editor you will see that Y1 contains the regression equation.
If you have already drawn the scatter plot for your data, pressing GRAPH will superpose the scatter plot and the regression curve., and you will be able to judge the goodness of the fit.

Step 0: Press the ON key at the lower left corner of the keyboard to turn the calculator on.

The next 13 steps are at the beginning of Chapter 12 of the guidebook.

You don't do anything for the Casios.. If the correlation and determination coefficients have a meaning in the regression model (such as linear regression) they will be calculated and displayed automatically on the same screen where the regression equation is displayed. However if the regression model has no such coefficients nothing will be displayed.

The general answer is no. However the calculator can be used to find the slope and the y-intercept. You write the formula for the rate of change (a) and use the calculator to calculate it. Then you use the formula to find the y-intercept.
If you have 2 points, you can use the 2 -var statistics program to find a linear regression.

Assuming your two point coordinates are of the form (x1, y1) and (x2, y2).
There are two possible methods:
You can use the slope formula which is commonly known as "rise over run." To do this: slope = (y2 - y1) / (x2 - x1) This means that the vertical distance covered by the two points divided by the horizontal distance covered by the two points is equal to the slope.
You can use your calculator's linear regression capabilities:
First step: Press the STAT button (next to the arrow keys toward the top right of your calculator).
Second: Select the first option, Edit...
Third: Under L1, enter your first x value, press enter, enter your second x value, press enter again.
Fourth: Under L2, enter your first y value, press enter, enter your second y value, press enter again.
Fifth: Press the STAT button again. Press the right arrow button to highlight CALC.
Sixth: Select the fourth option LinReg(ax+b).
Seventh: Press 2ND then 1 (L1 should show up on your screen). Then press the comma button (right above the number 7). Press 2ND then 2 (L2 should show up on your screen). Press ENTER.
Eighth: Once you press ENTER, several values will appear. The a value is the slope of the two coordinates.

(-19) + 9 + (-3)

I assume you know how to enter data in your calculator. The keystrokes in the following pertain to TI92/92Plus/ Voyage 200 PLT. The main differences with the TI89/Ti89 Titanium is that the function keys F6,F7,F8 are not accessed directly but by the key sequences [2nd][F1], [2nd][F2], and [2nd][F3] respectively

1. CLEAN THE SLATE (so to speak) and ENTER DATA

In Home folder run F6: NewProb to reset the configuration.
Press Apps, and select 6: data/Matrix editor. Select a new data set


Give it a name: here testing.



Press OK/ENTER, The data entry screen opens, enter your values.


When you finish press F2.PlotSetUp.

2. Statistical plot setup and scatter plot drawing

.

Press F1:define to configure Plot1. Choose Scatter, then choose a mark for the data point. I select 5:Dot. and press [ENTER


Select the data column X=c1, Y=c2



Press ENTER to save configuration. Press [CTRL] [GRAPH] On my TI92 the CTRL key is the [Diamond] key. On the following graph I changed the mark to a cross to see the data point better. I also played with the window dimension. You can also do that with ZoomStat. The graph remind me of a parabola (I know I chose the exact values)



3. STATISTICAL CALC. AND REGRESSION ANALYSES.

Now we have to find the equation that fits these data best.
You press APPS 6:Data/ Matrix editor but you select current to return to your data set. You are taken to the data entry editor (Figure 3 above). In that screen Press F5:Calc to edit the type of statistics you want

On first line select the type of regression model : Linear Regression, QuadReg quadratic regression (or anything else available) X is from column1, Y is from column 2. Store RegEQ The regression equation in say Y1(x)



Press ENTER to save to get the Regression Equation. Here it is
As you can see I cheated: a perfect parabola. R^2 =1.



And here the best fit represented on same graph as the statistical data



Usually you have to try different regression models, until you find the one that fits best the experimental data.

Start by creating the data lists.

CREATE THE X-LIST

1. Press Home.
   
2. Use navigation pad to Highlight [3: Lists and Spreadsheets]
3. Press Enter
   
4. A list opens with cursor in Cell A1.
   
5. Use UpArrow to move the cursor to the header of the list and give it a name, say X.
6. Press Enter. Cursor moves to Cell A1
7. Enter an X-value in each cell and press ENTER to move to next cell:
   
8. Type 1, and press ENTER. Say Yes to overwrite message by pressing OK.
9. Enter 2,3,4,5,6,7,8,9,10 (just a bogus sample).

CREATE THE Y-LIST

1. After typing 10 in cell A10, press ENTER to validate.
2. Use the Navigation pad to move cursor to the head of the B column.
3. Give it a name , say Y.
4. Press ENTER, Cursor moves to cell B1.
5. As for X-list, enter the Y values. Here is a sample (-2, -1, 0, 1,2,3,4,5,6,7). After you type value in B1, accept the overwrite message by pressing OK. Type the other values.
6. Make sure that the X-List and Y-List have the same number of elements, otherwise you will have a dimension mismatch error.

DOING A REGRESSION

1. While the lidt is still displyed, prress the Menu key
2. Highlight [4:Statistics]
3. Use Right Arrow to unfold submenu list and select [1:Stat Calculations]
4. Use right Arrow to unfold the submenu list and
5. Select [3:Linear regression (mx+b)] or [4:linear regression (ax+b)]

That is what you see.

Using Tab to move from one line to the next, configure the calculator as seen on the next screen.

And the last line is at the bottom of the next screen capture


The statistical results will hence be displayed in the C[] column.
Use TAb to move focus to OK, and press ENTER.
Here they are.


You can recognize each statistical results, RegEq is y=mx+b. You also have m, b, r^2, and r. The residuals appear on the next row. By highlighting the cell with the {0.,0...0} you can display the hidden values


Here you have all you asked for. But you can go further by drawing the curve.

The regression equation is stored in function f1, so you have to draw the f1 function. .

DRAWING THE REGRESSION CURVE

Press the HOME button
Highlight and select [2:Graphs and Geometry]
At the bottom of the screen there is a command line with f2(x)=
Use the UpArrow to display the f1(x)= equation


Press ENTER to draw the function f1


I think I have to stop here. There is enough material to get you started.
I left for you the part where you draw the data points. read the user manual.