In: Statistics and Probability
he 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% | 50 |
5 to 14 | 13.6% | 78 |
15 to 64 | 67.1% | 281 |
65 and older | 12.1% | 46 |
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 the same.
H0: The distributions are different.
H1: The distributions are
different. H0: The
distributions are the same.
H1: The distributions are different.
H0: The distributions are different.
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?
Yes
No
What sampling distribution will you use?
Student's t uniform
chi-square binomial
normal
What are the degrees of freedom?
(c) 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 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.
The expected values have been calculated where each expected value = (5/100) * Total. Total = 455
Age(years) | % | Expected Value | Observed Value |
Under 5 | 7.2% | (7.2/100) * 455 = 32.760 | 50 |
5 to 14 | 13.6% | (13.6/100) * 455 = 61.880 | 78 |
15 to 64 | 67.1% | (67.1/100) * 455 = 305.305 | 281 |
65 and older | 12.1% | (12.1/100) * 455 = 55.055 | 46 |
Total | 100% | 455 | 455 |
(a) The Level of significance = 0.05
The Hypothesis:
H0: The Distributions are the same.
Ha: The Distributions are different.
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(b) The Test Statistic: The table below gives the calculation of .
Observed | Expected | O-E | (O-E)2 | (O-E)2/E |
50 | 32.76 | 17.24 | 297.2176 | 9.07257631 |
78 | 61.88 | 16.12 | 259.8544 | 4.19932773 |
281 | 305.305 | -24.305 | 590.733025 | 1.9348947 |
46 | 55.055 | -9.055 | 81.993025 | 1.48929298 |
455 | 455 | Total | 16.696 |
test = 16.696
YES, all the expected frequencies are greater than 5.
The sampling distribution to be used is the CHI square Distribution
The degrees of freedom, df = n - 1 = 4 - 1 = 3
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(c) The p value: The p value at = 16.696, df = 3, is P value = 0.0008.
Therefore the range in which the p value lies is Option 6: p value < 0.005.
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(d) The Decision: Option 3 - Since p value is , we reject the null Hypothesis.
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(e) The Conclusion: Option 2 - At the 5% level of significance, there is sufficient evidence to conclude that the village population does not fit the general Canadian population.
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