Download Stats on the TI-84+

Stats on the TI-84+
9/15/2014
Stats on the TI-84+
Topics
Notation
Problems and Errors
Lists and Matrices
Enter a new list
Edit an existing list
Clear a list
Enter or edit a matrix
Descriptive statistics
Find the mean or median
Find the range
Find the population variance or standard deviation
Find the sample variance or standard deviation
Find quartiles
Stats for grouped data
Use a computed statistic
Displays
Construct a frequency histogram
Construct a box-and-whisker plot
Construct a line graph
Construct a scatter plot
The binomial distribution
Binomial distribution: probability of exactly x successes
Binomial distribution
Binomial distribution: probability of at least x successes
The normal distribution
Probabilities for x~N(μ,σ)
Construct a normal probability plot
Confidence intervals
z Confidence interval (σ known)
t Confidence interval (σ unknown)
Hypothesis tests
Z-Test (σ known)
T-Test (σ unknown)
Correlation and regresssion
r and trendline coefficients
Add a trendline to a scatter plot
Notation
On the TI-84+:
Sx means the sample standard deviation s
σx means the population standard deviation σ
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Problems and Errors
INVALID DIM when graphing
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You may have several functions defined, one of which is invalid under the current conditions. Press Y= and clear them.
You may have multiple plots turned on. Press Y= and make sure that only one of Plot 1, Plot 2, or Plot 3 is highlighted.
If you are using multiple lists, you may have two lists of different lengths.
You may have deleted a built-in list. Press STAT , then 5 , then ENTER .
List L1 is gone
1. STAT
2. Choose 5:SetUpEditor
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3. ENTER
Normal probability plot does not appear
Press ZOOM , then 9.
LinReg does not show r
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CATALOG (= 2ND 0 )
x-1 (to get to the Ds)
Arrow down to DiagnosticOn
ENTER
Weird error which won't go away
Try resetting all RAM, which erases temporary memory only:
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MEM (= 2ND + )
Choose 7:Reset
Choose 1:All RAM
Choose 2:Reset
ENTER
Try resetting defaults:
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MEM (= 2ND + )
Choose 7:Reset
Choose 2:Defaults
Choose 2:Reset
ENTER
If these don't work, you need an expert (not me, I'm afraid).
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Enter a new list
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STAT
Choose 1:Edit (the default)
Arrow over to the list (L1–L6) you want
Type a number, hit ENTER ; repeat
Quit the list editor: QUIT (= 2ND MODE )
If you chose list L1, your list will be stored in the variable L1 (= 2ND 1 ), and so on.
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Edit an existing list
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STAT
Choose 1:Edit (the default)
Arrow to list entry you want to change
To delete the highlighted entry: DEL
To change the highlighted entry: type a number, hit ENTER
To insert an entry above the highlighted entry: INS (= 2ND DEL )
To quit the list editor: QUIT (= 2ND MODE )
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Clear a list
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STAT
Choose 1:Edit (the default)
Arrow over to the list you want to clear
Arrow up to highlight the list name
CLEAR
ENTER
To quit the list editor: QUIT (= 2ND MODE )
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Enter or edit a matrix
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MATRIX (= 2ND x-1
Arrow over to EDIT
)
Arrow down to the matrix you wish to edit
ENTER
Enter the number of rows and press ENTER
Enter the number of columns and press ENTER
Enter the matrix entries, pressing ENTER after each
To quit the matrix editor: QUIT (= 2ND MODE )
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Find the mean or median
This assumes that you have put a list in L1.
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STAT
Choose 1:1-Var Stats (the default)
ENTER
ENTER
Arrow down to x̄ or Med
To use the mean or median in a computation, see the section on using a computed statistic.
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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 xmax – xmin.
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STAT
Choose 1:1-Var Stats (the default)
ENTER
ENTER
VARS
Choose 5:Statistics
Arrow down to maxX
ENTER
Press – (the subtraction key)
VARS
Choose 5:Statistics
Arrow down to minX
ENTER
ENTER
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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.
1. Find the population standard deviation:
1. STAT
2. Arrow over to CALC
3. Choose 1:1-Var Stats (the default)
4. ENTER
5. ENTER
6. Arrow down to find σx
2. Find the population variance:
1. VARS
2. Choose 5:Statistics
3. Arrow down to σx
4. ENTER puts it on the main screen
5. ENTER again to see its value
6. x2
7. ENTER
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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.
1. Find the sample standard deviation:
1. STAT
2. Arrow over to CALC
3. Choose 1:1-Var Stats (the default)
4. ENTER
5. ENTER
6. Arrow down to find Sx
2. Find the sample variance:
1. VARS
2. Choose 5:Statistics
3. Arrow down to Sx
4. ENTER puts it on the main screen
5. ENTER again to see its value
6. x2
7. ENTER
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Find quartiles
This assumes that you have put a list in L1.
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STAT
Arrow over to CALC
Choose 1:1-Var Stats (the default)
ENTER
ENTER
Arrow down to find Q1 , Med, and Q3
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Stats for grouped data
This assumes that you have put your data (or midpoints) in L1 and your frequencies in L2.
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STAT
Arrow over to CALC
Choose 1:1-Var Stats (the default)
ENTER
2ND 1
to get L1
Press , (the comma key)
2ND 2 to get L2
ENTER
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Use a computed statistic
This assumes that you have put a list in L1.
1. If you haven’t done so already, compute stats:
1. STAT
2. Arrow over to CALC
3. Choose 1:1-Var Stats (the default)
4. ENTER
5. ENTER
2. Use a computed stat:
1. VARS
2. Choose 5:Statistics
3. Arrow down to the stat you want
4. ENTER puts it on the main screen
5. If you wish, ENTER again to see its value
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You can select a variable from VARS at any time. To see an example of this within a calculation, see the section on range.
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Construct a frequency histogram
This assumes that you have put the data in L1.
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STAT PLOT (= 2ND Y=
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Arrow down to desired stat plot (default is 1)
ENTER to get stat plot options
Arrow to On and press ENTER
Arrow to
and press ENTER
ENTER
If Xlist is not already set to L1:
1. Arrow down to Xlist (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
8. Set Freq to 1
9. Use WINDOW to set window params:
1. Set Xmin = lower limit of lowest class
2. Set Xmax = upper limit of highest class
3. Set Xscl = class width
4. Set Ymin = 0
5. Set Ymax = a value near but ≥ max frequency (you may have to play with this)
10. GRAPH
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Construct a box-and-whisker plot
This assumes that you have put a list in L1 consisting of xmin, Q1, Q2, Q3, and xmax in that order.
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STAT PLOT (= 2ND Y=
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Arrow down to desired stat plot (default is 1)
ENTER to get stat plot options
Arrow to On and press ENTER
Arrow to , press ENTER
ENTER
If Xlist is not already set to L1:
1. Arrow down to Xlist (do not press ENTER)
2. LIST (= 2ND STAT )
3. ENTER
8. Use WINDOW to set window params
9. GRAPH
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Construct a line graph
This assumes that you have put your x-coordinates in L1 and your y-coordinates in L2.
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STAT PLOT (= 2ND Y=
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Arrow down to desired stat plot (default is 1)
ENTER to get stat plot options
Arrow to On and press ENTER
Arrow to
and press ENTER
If Xlist is not already set to L1:
1. Arrow down to Xlist (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
7. If Ylist is not already set to L2:
1. Arrow down to Xlist (do not press ENTER )
2. LIST (= 2ND STAT )
3. Arrow down to L2
4. ENTER
8. Use WINDOW to set window params
9. GRAPH
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Construct a scatter plot
This assumes that you have put your x-coordinates in L1 and your y-coordinates in L2.
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STAT PLOT (= 2ND Y=
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Arrow down to desired stat plot (default is 1)
ENTER to get stat plot options
Arrow to On and press ENTER
Arrow to
and press ENTER
If Xlist is not already set to L1:
1. Arrow down to Xlist (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
7. If Ylist is not already set to L2:
1. Arrow down to Xlist (do not press ENTER )
2. LIST (= 2ND STAT )
3. Arrow down to L2
4. ENTER
8. Use WINDOW to set window params
9. GRAPH
You can add a trendline to a scatter plot.
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Binomial distribution: probability of exactly x successes
To find the probability of exactly x successes in n Bernoulli trials with P(success) = p:
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DISTR (= 2ND VARS )
Arrow down to binompdf
ENTER
Enter your values of n, p, and x, separated by commas
ENTER
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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:
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STAT
Choose 1:Edit (the default)
Arrow over to L1
Arrow up to the L1 list header
LIST (= 2ND STAT )
Arrow over to OPS
Arrow down to 5: seq(
ENTER to make seq( appear in list editor
Press X,T,Θ,n , X,T,Θ,n , 0 , and then your value of n (you are entering X,X,0,n)
ENTER
Now get the binomial probabilities into L2:
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Arrow over to L2
Arrow up to the L2 list header
DISTR (= 2ND VARS )
Arrow down to binompdf(
Enter n and p, separated by a comma
ENTER
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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
1. 1 2. DISTR (= 2ND VARS )
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3. Arrow down to binomcdf(
4. Enter n, p, and x, separated by commas
5. ENTER
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Probabilities for x~N(μ,σ)
Given c, find P(x<c):
Use normalcdf(-10000,c,μ,σ):
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DISTR (= 2ND VARS )
Arrow down to normalcdf(
ENTER to put normalcdf( on the screen
Type in the values, separated by commas
ENTER
Given a probability p, find c such that P(x<c) = p:
Use invNorm(p,μ,σ):
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DISTR (= 2ND VARS )
Arrow down to invNorm(
ENTER to put invNorm( on the screen
Type in the values, separated by commas
ENTER
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Construct a normal probability plot
This assumes that you have put the data in L1.
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STAT PLOT (= 2ND Y=
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Arrow down to desired stat plot (default is 1)
ENTER to get stat plot options
Arrow to On and press ENTER
Arrow down, then over to , press ENTER
If Data List is not already set to L1:
1. Arrow down to Data List (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
7. Arrow down to Data Axis
8. Arrow to X
9. ENTER
10. ZOOM
11. Choose 9:ZoomStat
12. ENTER
13. GRAPH (if necessary)
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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.
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STAT
Arrow to TESTS
Choose 7:ZInterval
Arrow to Stats and press ENTER
Arrow down to σ and enter the value of σ
Arrow down to x̄ and enter the value
Arrow down to n:. Set it to your value of n.
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8. Arrow down to C-Level: (confidence level) and set it (as a decimal)
9. Arrow down to Calculate
10. ENTER
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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:
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STAT
Arrow to TESTS
Choose 8:TInterval
Arrow to Data and press ENTER
If List: is not already set to L1:
1. Arrow down to List: (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
6. Arrow down to Freq:. Set it to 1.
7. Arrow down to C-Level: (confidence level) and set it (as a decimal)
8. Arrow down to Calculate
9. ENTER
If you know
the sample size n;
the sample mean x̄; and
the sample standard deviation Sx:
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STAT
Arrow to TESTS
Choose 8:TInterval
Arrow to Stats and press ENTER
Arrow down to x̄ and enter the value
Arrow down to Sx and enter the value
Arrow down to n:. Set it to your value of n.
Arrow down to C-Level: (confidence level) and set it (as a decimal)
Arrow down to Calculate
ENTER
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Z-Test (σ known)
You must know either that the population is approximately normal, or have n ≥ 30 (or both).
You will need
μ0;
the population standard deviation σx;
the sample mean x̄; and
the sample size n.
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STAT
Arrow to TESTS
Choose 1:Z-Test
Arrow to Stats and press ENTER
Arrow down to μ : and enter the value
Arrow down to σ: and enter the value
Arrow down to x̄: and enter the value
Arrow down to n: and enter the value
Arrow down to the line beginning μ:≠μ and choose your alternate hypothesis
ENTER
Arrow down to Calculate
ENTER
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T-Test (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:
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STAT
Arrow to TESTS
Choose 2:T-Test
Arrow to Data and press ENTER
Arrow down to μ : and enter the value
If List: is not already set to L1:
1. Arrow down to List: (do not press ENTER )
2. LIST (= 2ND STAT )
3. ENTER
7. Arrow down to Freq:. Set it to 1.
8. Arrow down to the line beginning μ:≠μ and choose your alternate hypothesis
9. ENTER
10. Arrow down to Calculate
11. ENTER
If you know
the sample size n;
the sample mean x̄;
the sample standard deviation Sx:
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STAT
Arrow to TESTS
Choose 2:T-Test
Arrow to Stats and press ENTER
Arrow down to μ : and enter the value
Arrow down to x̄ and enter the value
Arrow down to Sx and enter the value
Arrow down to n: and enter the value
Arrow down to the line beginning μ:≠μ and choose the alternate hypothesis
ENTER
Arrow down to Calculate
ENTER
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r and trendline coefficients
This assumes that you have put your x-coordinates in L1 and your y-coordinates in L2.
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STAT
Arrow over to CALC
Choose 4:LinReg(ax+b)
ENTER
ENTER
Numbers a, b, r, and r2 should be displayed. If r or r2 is not displayed, see the Problems and errors section.
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Add a trendline to a scatter plot
This assumes that you have put your x-coordinates in L1 and your y-coordinates in L2 and made a scatter plot.
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1. Get the coefficients a and b. Write them down.
2. Put ax+b in Y1 :
a. Press Y=
b. Arrow to \Y1 =
c. Type in the number you got for a
d. Press the * (multiply) key
e. Press the X,T,Θ,n key (to get X)
f. Press +
g. Type in the number you got for b
3. GRAPH
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