Transcript Chapter 3

Using calculator TI-83/84
1. Enter values into L1 list: press “stat”
2. Calculate all statistics: press “stat”
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Binomial Probability Formula
P(x) =
n!
•
(n – x )!x!
Number of
outcomes with
exactly x
successes
among n trials
px •
n-x
q
The probability of
x successes
among n trials for
any one particular
order
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Using TI-83/84
• Press 2nd VARS to get the DISTR
menu
• Scroll down to binomialpdf( and press
ENTER
• Type in three values: n, p, x (separated by
commas) and close the parenthesis
• You see a line like binomialpdf(10,.3,6)
• Press ENTER and read the probability of
the value x (successes) in n trials
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Alternative use of TI-83/84
• Press 2nd VARS to get the DISTR menu
• Scroll down to binomialcdf( and press
ENTER
• Type in three values: n, p, x (separated by
commas) and close the parenthesis
• You see a line like binomialcdf(10,.3,6)
• Press ENTER and read the combined
probability of all values from 0 to x
(i.e., probability that there are at most x
successes)
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Mean, Variance and
Standard Deviation of a
Probability Distribution
µ =  [x • P(x)]
Mean
 =  [(x – µ) • P(x)]
Variance
 =  [x • P(x)] – µ
Variance (shortcut)
2
2
2
=
2
2
 [x 2 • P(x)] – µ 2
Standard Deviation
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Using TI-83/84 calculator
• Press the STAT button and choose EDIT
• Enter the x-values into the list L1 and the
P(x) values into the list L2
• Press the STAT button and choose CALC
• Choose
1-Var Stats and press ENTER
• Type in L1 then , (comma) then L2 on that
line, you will see
1-Var Stats L1,L2
• Press ENTER
• You will see x-bar=…, it is actually m (mean)
and x=…, it is actually  (st. deviation)
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Methods for Finding Normal
Distribution Areas
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Normal Distribution by TI-83/84
• Press 2nd VARS to get the DISTR
menu
• Scroll down to normalcdf( and press
ENTER
• Type in two values: Lower, Upper
(separated by commas) and close the
parenthesis
• You see a line like normalcdf(-2.00,1.50)
• Press ENTER and read the probability.
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Normal Distribution by TI-83/84
(continued)
If you do not have an upper value, type 999.
Example: for P(z>1.2) enter normalcdf(1.2,999)
If you do not have a lower value, type -999.
Example: for P(z<0.6) enter normalcdf(-999,0.6)
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Inverse Normal by TI-83/84
• Press 2nd VARS to get the DISTR
menu
• Scroll down to invNorm( and press
ENTER
• Type in the desired area and close the
parenthesis
• You see a line like invNorm(0.95)
• Press ENTER and read the z-score.
• Round off to three decimal places.
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Normal Distribution by TI-83/84
• Press 2nd VARS to get the DISTR
menu
• Scroll down to normalcdf( and press
ENTER
• Type in four values: Lower, Upper, Mean,
St.Deviation (separated by commas) and
close the parenthesis
• You see a line like
normalcdf(-999,174,172,29)
• Press ENTER and read the probability.
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Inverse Normal by TI-83/84
• Press 2nd VARS to get the DISTR
menu
• Scroll down to invNnorm( and press
ENTER
• Type in the desired area, mean,
st.deviation and close the parenthesis
• You see a line like
invNorm(0.995,172,29)
• Press ENTER and read the x-score.
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