Download More Binomial Using Calculator

The probability that a person will subscribe to Statistics
Monthly is 48%. Find the probability that out of a group of
seven, at least one person subscribes.
There are charts as well – but only for some
probabilities so you need to know the formula.
MORE BINOMIAL
USING CALCULATOR
Section 6.3B
Using the calculator to find binomial
probabilities.
• To find exactly 1 probability:
binompdf(n, p, x)
Press:
2nd Distribution
0 binompdf(n,p,x)
n – for number of trials
p – for given percent
x - # we want
A tourist bureau for a western state conducted a study, which
showed that 65% of the people who seek information about the
state actually come for a visit. The office receives 15 requests for
information on the state. Find the probability that exactly 10 visit.
• Binompdf(15, 0.65, 10)
• You should get 0.2123 or 21.2%
Remember: PDF is for exactly
To accumulate probabilities – adding
more than one- we use binomcdf.
• It accumulates starting with x = 0 up to the value you
want.
• It’s under 2nd distribution
A binomcdf (n, p, x)
A survey found that 30% of teens get spending money from
part time jobs. If 5 teens are selected at random find the
probability that at most 3 of them have part time jobs.
x
p(x)
0
0.16807
1
0.36015
2
0.3087
3
0.1323
4
0.02835
5
0.00243
0.96922
On the calculator:
Binomcdf(5, 0.30,3)
A survey found that 30% of teens get spending money from part
time jobs. If 5 teens are selected at random find the probability
that at least 3 of them have part time jobs.
x
p(x)
0
0.16807
On the calculator:
1
0.36015
Binomcdf(5, 0.30,2)= 0.83692
2
0.3087
3
0.1323
4
0.02835
5
0.00243
0.16308
1 - Binomcdf(5, 0.30,2) = 0.16308
To do the bottom of the list:
• You accumulate the top part of the distribution.
• Subtract from 1.
A survey found that 30% of teens get spending money from part
time jobs. If 5 teens are selected at random find the probability
that more than 3 of them have part time jobs.
x
p(x)
0
0.16807
1
0.36015
On the calculator:
Binomcdf(5, 0.30,2)= 0.96922
2
0.3087
3
0.1323
4
0.02835
5
0.00243
0.03078
1 - Binomcdf(5, 0.30,3) = 0.03078
Tim did not study for his quiz with 5 multiple choice (A, B, C, D)
questions.
Hint: Probability of correct choice is ¼ = 0.25!
• What is the probability that he got exactly 3 correct?
• What is the probability that he got at most 2 correct?
• What is the probability that he got more than 3
correct?
A certain type of penicillin will cause a skin rash in
35% of the patients receiving it.
• If the penicillin is given to a random sample of 15
patients what is the probability that at least 7 will
have a skin rash?
• If it is given to a random sample of 9 patients, what is
the probability that at least one will have a skin rash?
• If it is given to a random sample of 12 patients, what
is the probability that exactly 5 will have a skin rash?
Homework
*Worksheet