Question

The following table shows the Myers-Briggs personality preferences for a random sample of 519 people in the listed professions. T refers to thinking and F refers to feeling.

	Personality Type
Occupation	T	F	Row Total
Clergy (all denominations)	55	93	148
M.D.	81	78	159
Lawyer	115	97	212
Column Total	251	268	519

Use the chi-square test to determine if the listed occupations and personality preferences are independent at the 0.01 level of significance.

(a) What is the level of significance?


State the null and alternate hypotheses.

H₀: Myers-Briggs preference and profession are not independent.
H₁: Myers-Briggs preference and profession are independent.

H₀: Myers-Briggs preference and profession are independent.

H₁: Myers-Briggs preference and profession are 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 not 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 or No    

What sampling distribution will you use?

Student's t

normal    

uniform

chi-square

binomial

What are the degrees of freedom?


(c) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.)


(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 > ?, we fail to reject the null hypothesis.Since the P-value > ?, we reject the null hypothesis.    Since the P-value ? ?, we reject the null hypothesis.Since the P-value ? ?, we fail to reject the null hypothesis.

(e) Interpret your conclusion in the context of the application.

At the 1% level of significance, there is insufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.

At the 1% level of significance, there is sufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.  

Answer 1

Ans:

a)Level of significance=0.01

H0: Myers-Briggs preference and profession are independent.
H1: Myers-Briggs preference and profession are not independent.

b)

	Observed freq.(fo)
Occupation	T	F	Row Total
Clergy (all denominations)	55	93	148
M.D.	81	78	159
Lawyer	115	97	212
Column Total	251	268	519
	Expected freq.(fe)
Occupation	T	F	Row Total
Clergy (all denominations)	71.576	76.424	148
M.D.	76.896	82.104	159
Lawyer	102.528	109.472	212
Column Total	251	268	519
	Chi square=(fo-fe)^2/fe
Occupation	T	F	Row Total
Clergy (all denominations)	3.839	3.595	7.434
M.D.	0.219	0.205	0.424
Lawyer	1.517	1.421	2.938
Column Total	5.575	5.221	10.796

Chi square test statistic=10.796

Yes,all the expected frequencies greater than 5.

chi-square

DF=(3-1)*(2-1)=2

c)p-value=CHIDIST(10.796,2)=0.005

d)Since the P-value ? ?, we reject the null hypothesis

e)At the 1% level of significance, there is sufficient evidence to conclude that Myers-Briggs preference and the profession are not independent.