Additional handout: Use of Ti-84 Plus GC for tabulating
probability in a table format
With reference to Q14(iii) of Assignment 2 in Binomial
Distribution
[ACJC 08/Q8]
A firm receives a large number of job applications from
graduates each year. On average 20% of applications are
successful. A researcher in the human resource department of the
firm selects a random sample of 22 graduate
applicants.
(iii) Find the modal number of successful applicants in the
sample.
Note: in this question, Let X be the number of successful
applicants, out of 22.
~ (22,0.2)X B
Aim: To find the ? such that ?P X gives the largest
probability
GC steps:
S/N Idea Steps Screen Captures
1 Use the Graph-mode to enter
the binomial distribution
model and enter the important
information: trials: 22,
p=0.2, x-value: X.
*If it does not prompt you to
enter in the values, please do
so on your own by keying the
corresponding values
2 To view the probabilities in the
table format
3 Scroll down to run through the
values and observe the one that
gives the highest probability
Solution to be presented:
Let X be the number of successful applicants, out of 22.
~ (22,0.2)X B
From GC,
P(X = 3) = 0.17755
P(X = 4) = 0.21084 (Highest probability)
P(X = 5) = 0.18976
Hence, the modal number is 4.
**EXTENSION: To create a list of values for P X r , just change
from binompdf to binomcdf.
*Please write down 3 consecutive
probabilities and identify the one
that has the highest probability!
Additional handout: Use of Casio GC for tabulating probability
in a table format
With reference to Q14(iii) of Assignment 2 in Binomial
Distribution
A firm receives a large number of job applications from
graduates each year. On average 20% of applications are
successful. A researcher in the human resource department of the
firm selects a random sample of 22 graduate
applicants.
(iv) Find the modal number of successful applicants in the
sample.
Note: in this question, Let X be the number of successful
applicants, out of 22.
~ (22,0.2)X B
Aim: To find the ? such that ?P X gives the largest
probability
GC steps:
S/N Idea Steps Screen Captures
1 Use the Stat-mode:
Scroll up to List 1, with the
cursor at List 1, enter a
sequence of numbers from 1 to
22 (because n=22)
2 BB uiqy
f,f,0, 22,1kl
2 Move cursor to List 2
Enter the binomial distribution
bpd
Since we want the
probabilities of the values
from List 1, we select List.
$
ddyyq
Scroll down to enter in the
Numtrial, p and save Res in
List 2
NN22l0 .2lw2l
3 Return to the list of values
Scroll down to run through the
values and observe the one that
gives the highest probability
ldd
Solution to be presented:
Let X be the number of successful applicants, out of 22. ~
(22,0.2)X B
From GC,
P(X = 3) = 0.17755
P(X = 4) = 0.21084 (Highest probability)
P(X = 5) = 0.18976
Hence, the modal number is 4.
**EXTENSION: To create a list of values for P X r , just change
from binomial pd to binomial cd.
