Statistical Distributions - HP RPN SCIENTIFIC WP 34S Owner's Manual

Statistical Distributions

Stack-wise, the following are all one-number functions. They are all stored in PROB. In the
table below, the three discrete distributions are covered first, the continuous ones
thereafter. Typical plots are shown for the pmfs or the pdfs, respectively.
Name Remarks (see p.
Binomial distribution with the number of
successes g in
of a success p
K
n in .
Binom returns
P
p ( g
B
Binom returns
Binom
F ( m
B
The binomial distribution is fundamental for error statistics in industrial sampling, e.g. for
designing test plans. If you want to know, for example, the probability for finding no
faulty items in a sample of fifteen items drawn from a batch of 300 wherein you expect
3% defective items overall, this will tell you:
0.03
out of three that you will not detect any defect in your sample!
Read here for more information:
http://www.itl.nist.gov/div898/handbook/eda/section3/eda366i.htm
Geometric distribution:
Geom returns
P
Geom returns
being the probability for a first success
after m =
Geom
probability p
experiment must be specified in
Start reading here for more:
http://en.wikipedia.org/wiki/Geometric_dist
ribution .
84
Binom equals BINOMDIST(g; n; p
P
85
The exact result for said probability is 0.626, calculated using a mathematically more elaborated model of
such a test. These results show nicely that two significant digits are a typical accuracy of statistical
statements – frequently the (simplified) statistical model used matches reality no better than that.
WP 34S Owner's Manual
74 for general information)
X , the gross probability
J
in and the sample size
0
 
n

      
g
; n ; p ) p 1
0 0
 
g

  
g
C p 1
n , g 0
(see COMB above).
m


; n ; p ) p ( g ; n ;
0 B

g 0
 
15
  

f n p 1
Ge 0
  
 
F m 1 1
Ge
x
Bernoulli experiments. The
for a success in each such
0
; 0) and Binom equals BINOMDIST(m; n; p
0



n g
p
0



n g
p
0
with the maximum number of successes m in
p )
0
0 Binom returns 0.633 – so the odds are almost two

n
p
,
0



m 1
p
,
0
J
.
Edition 3.1
84
X .
85
.
; 1) in MS Excel.
0
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