Notation 
On the TI84+: 
Sx means the sample standard deviation s 
σx means the population standard deviation σ 
Problems and Errors 
INVALID DIM when graphing 

List L1 is gone 

Normal probability plot does not appear 
Press ZOOM, then 9. 
LinReg does not show r 

Weird error which won't go away 
Try resetting all RAM, which erases temporary memory only:

Try resetting defaults:

If these don't work, you need an expert (not me, I'm afraid). 
Enter a new list 

If you chose list L1, your list will be stored in the variable L1 (= 2ND 1), and so on. 
Edit an existing list 

Clear a list 

Enter or edit a matrix 

Find the mean or median 
This assumes that you have put a list in L1. 

To use the mean or median in a computation, see the section on using a computed statistic. 
Find the range 
This assumes that you have put a list in L1. 
Your calculator does not find the range explicitly. Instead you must compute x_{max} – x_{min}. 

Find population variance or standard deviation 
This assumes that you have put a list in L1. 
Your calculator does not find the population variance directly. You find the population standard deviation and square it. 

Find sample variance or standard deviation 
This assumes that you have put a list in L1. 
Your calculator does not find the sample variance directly. You find the sample standard deviation and square it. 

Find quartiles 
This assumes that you have put a list in L1. 

Stats for grouped data 
This assumes that you have put your data (or midpoints) in L1 and your frequencies in L2. 

Use a computed statistic 
This assumes that you have put a list in L1. 

You can select a variable from VARS at any time. To see an example of this within a calculation, see the section on range. 
Construct a frequency histogram 

This assumes that you have put the data in L1.  

Construct a boxandwhisker plot 

This assumes that you have put a list in L1 consisting of x_{min}, Q_{1}, Q_{2}, Q_{3}, and x_{max} in that order.  

Construct a line graph 

This assumes that you have put your xcoordinates in L1 and your ycoordinates in L2.  

Construct a scatter plot 

This assumes that you have put your xcoordinates in L1 and your ycoordinates in L2.  


You can add a trendline to a scatter plot. 
Binomial distribution: probability of exactly x successes 
To find the probability of exactly x successes in n Bernoulli trials with P(success) = p: 

Binomial distribution 
To display a binomial distribution for n trials each having P(success) = p 
Lists L1 and L2 should be cleared before beginning. 
First get the numbers of successes into L1: 

Now get the binomial probabilities into L2: 

Binomial distribution: probability of at least x successes 
To find the probability of at least x successes in n Bernoulli trials with P(success) = p 

Probabilities for x~N(μ,σ) 
Given c, find P(x<c): Use normalcdf(10000,c,μ,σ):

Given a probability p, find c such that P(x<c) = p: Use invNorm(p,μ,σ):

Construct a normal probability plot 

This assumes that you have put the data in L1.  

z Confidence interval (σ known) 
You must either know that the population is approximately normal, or have n ≥ 30 (or both). 
You will need the sample size n; the sample mean x̄; and the population standard deviation σx.

t Confidence interval (σ unknown) 
You must be able to apply the CLT. There are different procedures depending on whether you have data or stats. 
If you have put the data in L1:
the sample size n; the sample mean x̄; and the sample standard deviation Sx:

ZTest (σ known) 
You must know either that the population is approximately normal, or have n ≥ 30 (or both). 
You will need μ_{0}; the population standard deviation σx; the sample mean x̄; and the sample size n.

TTest (σ unknown) 
You must be able to apply the CLT. There are different procedures depending on whether you have data or stats. 
If you have put the data in L1:
the sample size n; the sample mean x̄; the sample standard deviation Sx:

r and trendline coefficients 
This assumes that you have put your xcoordinates in L1 and your ycoordinates in L2. 

Numbers a, b, r, and r^{2} should be displayed. If r or r^{2} is not displayed, see the Problems and errors section. 
Add a trendline to a scatter plot 
This assumes that you have put your xcoordinates in L1 and your ycoordinates in L2 and made a scatter plot. 

Chisquare goodnessoffit test 
If you have a TI84+, you may be able to perform this test more simply. 
This assumes that you have put your observed values in L1 and your expected values in L2 and that you have cleared List L3. There are two stages to the procedure. 
Compute χ^{2}:

Compute the pvalue:

Chisquare independence test 
This assumes that you have put your observed values in Matrix A and your expected values in Matrix B. 

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