Question

The age distribution of the Canadian population and the age distribution of a random sample of 455 residents in the Indian community of a village are shown below.

Age (years)	Percent of Canadian Population	Observed Number in the Village
Under 5	7.2%	46
5 to 14	13.6%	83
15 to 64	67.1%	282
65 and older	12.1%	44

Use a 5% level of significance to test the claim that the age distribution of the general Canadian population fits the age distribution of the residents of Red Lake Village.

(a) What is the level of significance?


State the null and alternate hypotheses.

H₀: The distributions are the same.
H₁: The distributions are different.

H₀: The distributions are different.
H₁: The distributions are different.  

  H₀: The distributions are different.
H₁: The distributions are the same.

H₀: The distributions are the same.
H₁: The distributions are the same.

(b) Find the value of the chi-square statistic for the sample. (Round your answer to three decimal places.)


Are all the expected frequencies greater than 5?

What sampling distribution will you use?

Student's t

binomial   

uniform

chi-square

normal

What are the degrees of freedom?


(c) Estimate the P-value of the sample test statistic.

P-value > 0.1000

.050 < P-value < 0.100  

  0.025 < P-value < 0.0500

.010 < P-value < 0.0250

.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 that the population fits the specified distribution of categories?

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, the evidence is insufficient to conclude that the village population does not fit the general Canadian population.

At the 5% level of significance, the evidence is sufficient to conclude that the village population does not fit the general Canadian population.  

Answer 1

a)

level of significance =0.05

H₀: The distributions are the same.
H₁: The distributions are different

b)

applying chi square test:

	relative	observed	Expected	residual	Chi square
category	frequency	Oi	Ei=total*p	R2i=(Oi-Ei)/√Ei	R2i=(Oi-Ei)2/Ei
under 5	0.072	46	32.76	2.31	5.351
5 to 14	0.136	83	61.88	2.68	7.208
15 to 64	0.671	282	305.31	-1.33	1.779
65 and under	0.121	44	55.06	-1.49	2.220
total	1.000	455	455		16.558

  value of the chi-square statistic =16.558

Are all the expected frequencies greater than 5? Yes

What sampling distribution will you use? Chi square

What are the degrees of freedom? =4-1 =3

c)

P-value < 0.005

d)

  Since the P-value ≤ α, we reject the null hypothesis.

e)

At the 5% level of significance, the evidence is sufficient to conclude that the village population does not fit the general Canadian population.