In: Statistics and Probability
For parts (a)-(f) find the test statistic and p-values with the corresponding tables. Use chi-square distribution.
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) | 60 | 47 | 107 |
M.D. | 68 | 94 | 162 |
Lawyer | 55 | 82 | 137 |
Column Total | 183 | 223 | 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) 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.)
(b) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.)
(c) see below
Pottery Type | ||||
Site Type | Mesa Verde Black-on-White |
McElmo Black-on-White |
Mancos Black-on-White |
Row Total |
Mesa Top | 78 | 58 | 53 | 189 |
Cliff-Talus | 78 | 72 | 63 | 213 |
Canyon Bench | 96 | 66 | 64 | 226 |
Column Total | 252 | 196 | 180 | 628 |
Use a chi-square test to determine if site type and pottery type are independent at the 0.01 level of significance.
(c) 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.)
(d) see below
Age (years) | Percent of Canadian Population | Observed Number in the Village |
Under 5 | 7.2% | 43 |
5 to 14 | 13.6% | 85 |
15 to 64 | 67.1% | 277 |
65 and older | 12.1% | 50 |
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.
(d) Find the value of the chi-square statistic for the sample. (Round your answer to three decimal places.)
(e) Find or estimate the P-value of the sample test statistic. (Round your answer to four decimal places.)
(f) The type of household for the U.S. population and for a random sample of 411 households from a community in Montana are shown below.
Type of Household |
Percent of U.S. Households |
Observed Number of Households in the Community |
Married with children | 26% | 107 |
Married, no children | 29% | 98 |
Single parent | 9% | 34 |
One person | 25% | 103 |
Other (e.g., roommates, siblings) | 11% | 69 |
Use a 5% level of significance to test the claim that the distribution of U.S. households fits the Dove Creek distribution.
(f) Find the value of the chi-square statistic for the sample. (Round the expected frequencies to two decimal places. Round the test statistic to three decimal places.)
(i) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.)
E | I | Total | ||
Clergy (all denominations) | Observed | 60 | 47 | 107 |
Expected | 48.229 | 58.771 | 107.00 | |
O - E | 11.77 | -11.77 | 0.00 | |
(O - E)² / E | 2.87 | 2.36 | 5.23 | |
M.D. | Observed | 68 | 94 | 162 |
Expected | 73.020 | 88.980 | 162.00 | |
O - E | -5.02 | 5.02 | 0.00 | |
(O - E)² / E | 0.35 | 0.28 | 0.63 | |
Lawyer | Observed | 55 | 82 | 137 |
Expected | 61.751 | 75.249 | 137.00 | |
O - E | -6.75 | 6.75 | 0.00 | |
(O - E)² / E | 0.74 | 0.61 | 1.34 | |
Total | Observed | 183 | 223 | 406 |
Expected | 183.00 | 223.00 | 406.00 | |
O - E | 0.00 | 0.00 | 0.00 | |
(O - E)² / E | 3.96 | 3.25 | 7.20 | |
7.202 | chi-square | |||
2 | df | |||
.027 | p-value |
(a) 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.)
7.202
(b) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.)
0.027
Black-on-White | Black-on-White | Black-on-White | Total | ||
Mesa Top | Observed | 78 | 58 | 53 | 189 |
Expected | 75.841 | 58.987 | 54.172 | 189.00 | |
O - E | 2.16 | -0.99 | -1.17 | 0.00 | |
(O - E)² / E | 0.06 | 0.02 | 0.03 | 0.10 | |
Cliff-Talus | Observed | 78 | 72 | 63 | 213 |
Expected | 85.471 | 66.478 | 61.051 | 213.00 | |
O - E | -7.47 | 5.52 | 1.95 | 0.00 | |
(O - E)² / E | 0.65 | 0.46 | 0.06 | 1.17 | |
Canyon Bench | Observed | 96 | 66 | 64 | 226 |
Expected | 90.688 | 70.535 | 64.777 | 226.00 | |
O - E | 5.31 | -4.54 | -0.78 | 0.00 | |
(O - E)² / E | 0.31 | 0.29 | 0.01 | 0.61 | |
Total | Observed | 252 | 196 | 180 | 628 |
Expected | 252.00 | 196.00 | 180.00 | 628.00 | |
O - E | 0.00 | 0.00 | 0.00 | 0.00 | |
(O - E)² / E | 1.03 | 0.77 | 0.10 | 1.89 | |
1.889 | chi-square | ||||
4 | df | ||||
.756 | p-value |
(c) 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.)
1.889
observed | expected | O - E | (O - E)² / E | % of chisq |
43 | 32.760 | 10.240 | 3.201 | 21.44 |
85 | 61.880 | 23.120 | 8.638 | 57.87 |
277 | 305.305 | -28.305 | 2.624 | 17.58 |
50 | 55.055 | -5.055 | 0.464 | 3.11 |
455 | 455.000 | 0.000 | 14.927 | 100.00 |
14.927 | chi-square | |||
3 | df | |||
.0019 | p-value |
(d) Find the value of the chi-square statistic for the sample. (Round your answer to three decimal places.)
14.927
(e) Find or estimate the P-value of the sample test statistic. (Round your answer to four decimal places.)
0.0019
observed | expected | O - E | (O - E)² / E | % of chisq |
107 | 106.860 | 0.140 | 0.000 | 0.00 |
98 | 119.190 | -21.190 | 3.767 | 22.79 |
34 | 36.990 | -2.990 | 0.242 | 1.46 |
103 | 102.750 | 0.250 | 0.001 | 0.00 |
69 | 45.210 | 23.790 | 12.519 | 75.74 |
411 | 411.000 | 0.000 | 16.528 | 100.00 |
16.528 | chi-square | |||
4 | df | |||
.002 | p-value |
(f) Find the value of the chi-square statistic for the sample. (Round the expected frequencies to two decimal places. Round the test statistic to three decimal places.)
16.528
(i) Find or estimate the P-value of the sample test statistic. (Round your answer to three decimal places.)
0.002