In: Statistics and Probability
The following table shows the Myers-Briggs personality preferences for a random sample of 406 people in the listed professions. E refers to extroverted and I refers to introverted. |
Personality Type | |||
Occupation | E | I | Row Total |
Clergy (all denominations) | 65 | 42 | 107 |
M.D. | 66 | 96 | 162 |
Lawyer | 59 | 78 | 137 |
Column Total | 190 | 216 | 406 |
Use the chi-square test to determine if the listed occupations and
personality preferences are independent at the 0.05 level of
significance.
(a) What is the level of significance?
State the null and alternate hypotheses.
H0: Myers-Briggs preference and profession
are independent
H1: Myers-Briggs preference and profession are
independent
.H0: Myers-Briggs preference and profession
are not independent
H1: Myers-Briggs preference and profession are
not independent.
H0: Myers-Briggs preference and profession
are independent
H1: Myers-Briggs preference and profession are
not independent.
H0: Myers-Briggs preference and profession
are not independent
H1: Myers-Briggs preference and profession are
independent.
(b) Find the value of the chi-square statistic for the sample.
(Round the expected frequencies to at least three decimal places.
Round the test statistic to three decimal places.)
Are all the expected frequencies greater than 5?
Yes
No
What sampling distribution will you use?
binomial
chi-square
Student's t
normal
uniform
What are the degrees of freedom?
(c) Find or estimate the P-value of the sample test
statistic.
p-value > 0.100
0.050 < p-value < 0.100
0.025 < p-value < 0.050
0.010 < p-value < 0.025
0.005 < p-value < 0.010
p-value < 0.005
(d) Based on your answers in parts (a) to (c), will you reject or
fail to reject the null hypothesis of independence?
Since the P-value > α, we fail to reject the null hypothesis.
Since the P-value > α, we reject the null hypothesis.
Since the P-value ≤ α, we reject the null hypothesis.
Since the P-value ≤ α, we fail to reject the null hypothesis.
(e) Interpret your conclusion in the context of the
application.
At the 5% level of significance, there is insufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.
At the 5% level of significance, there is sufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.
a) level of significance =0.05
H0: Myers-Briggs preference and profession
are independent
H1: Myers-Briggs preference and profession are
not independent.
b)
Expected | Ei=row total*column total/grand total | E | I | Total |
Clergy | 50.07 | 56.93 | 107 | |
MD | 75.81 | 86.19 | 162 | |
Lawyer | 64.11 | 72.89 | 137 | |
total | 190 | 216 | 406 | |
chi square χ2 | =(Oi-Ei)2/Ei | E | I | Total |
Clergy | 4.4492 | 3.9136 | 8.363 | |
MD | 1.2701 | 1.1172 | 2.387 | |
Lawyer | 0.4078 | 0.3587 | 0.767 | |
total | 6.127 | 5.390 | 11.517 |
value of the chi-square statistic =11.517
Are all the expected frequencies greater than 5? :Yes
What sampling distribution will you use? :Chi square
degree of freedom(df) =(rows-1)*(columns-1)= | 2 |
c)
p-value < 0.005
d)
Since the P-value ≤ α, we reject the null hypothesis.
e)
At the 5% level of significance, there is sufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.