Homework SourseAnswer each question and show intermediate calculations Plea
Answer each question and show intermediate calculations. Please be heat! Do the work with a hand calculator by yourself 1. The arsenic concentration in groundwater was measured in samples from four locations near a landfill. Test the hypothesis that there are no significant differences in the mean arsenic concentrations in groundwater among the four sites at the 5% level of significance. (4 points) [Answers: SSG = 37.8, SSE = 65.2, F 2.32, Fo,o5 3.12 = 3.49.] 2. In a study of osteoporosis, bone density was measured in postmenopausal women. Women were chosen who had either had children or never gave birth from the four major ABO blood groups. There were four women for each combination of childrearing status and blood
Solution
we conduct chi square test for these 4 groups
H0: All 4 groups are identical
Ha: Atleast 2 are different
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Two-way Contingency Table
?2 = 55.890, df = 12, ?2/df = 4.66 , P(?2 > 55.890) = 0.0000
As p value is very low we reject null hypothesis i.e. atleast two are not identical
| 12 15.44 ( 0.77) | 9 10.12 ( 0.12) | 14 11.18 ( 0.71) | 10 8.25 ( 0.37) | 45 | |
| 14 16.82 ( 0.47) | 10 11.02 ( 0.09) | 17 12.18 ( 1.91) | 8 8.99 ( 0.11) | 49 | |
| 11 14.41 ( 0.81) | 7 9.44 ( 0.63) | 11 10.44 ( 0.03) | 13 7.70 ( 3.64) | 42 | |
| 8 6.86 ( 0.19) | 12 4.50 ( 12.52) | 0 4.97 ( 4.97) | 0 3.67 ( 3.67) | 20 | |
| 13 4.46 ( 16.34) | 0 2.92 ( 2.92) | 0 3.23 ( 3.23) | 0 2.38 ( 2.38) | 13 | |
| 58 | 38 | 42 | 31 | 169 |
