HP 39G Master Guide

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A teacher wishes to decide, at the 5%
level of significance, whether the
performance in a problem solving test
is independent of the students’ year
at school. The teacher selected 120
students, 40 from each of Years 8, 9
& 10, and graded their performance
in a test as either A or B.
The table above right shows the results.
The hypotheses being tested are:
H
0
: There is no relationship between grades awarded and years at
school. They are independent.
H
A
: There is a relationship.
If H
0
is true then the expected frequencies
should be those in the table on the right.
Enter the observed and expected frequencies
into columns C1 and C2 of the Statistics aplet.
In the HOME view, perform the calculation
shown right. This calculates the individual
2
χ
values ready for summing as per the
formula
()
2
2
OE
E
χ
−
=
∑
.
After first changing to the SYMB view to
register C3, the required total for C3 can be
found in the
view. In this case, 1.493.
Grade
awarded
Year A B Total
8 22 18 40
9 26 14 40
10 27 13 40
Total 75 45 120
Grade
awarded
Year A B Total
8 25 15 40
9 25 15 40
10 25 15 40
Total 75 45 120

HP 39G Specifications

General

Brand	HP
Model	39G
Category	Calculator
Language	English