There is an archaeological study area located in southwesternNew Mexico. Potsherds are broken pieces of prehistoric NativeAmerican clay vessels. One type of painted ceramic vessel is calledMimbres classic black-on-white. At three different sites,the number of such sherds was counted in local dwellingexcavations.
Site I | Site II | Site III |
69 | 28 | 15 |
30 | 17 | 35 |
24 | 53 | 65 |
10 | 68 | 20 |
77 | | 17 |
57 | | 15 |
26 | | |
Shall we reject or not reject the claim that there is nodifference in population mean Mimbres classic black-on-white sherdcounts for the three sites? Use a 1% level of significance.
(a) What is the level of significance?
State the null and alternate hypotheses.
H0: μ1 =μ2 = μ3;H1: Not all the means areequal.H0: μ1 =μ2 = μ3;H1: At least two means areequal.     H0:μ1 = μ2 =μ3; H1: Exactly two meansare equal.H0: μ1 =μ2 = μ3;H1: All three means are different.
(b) Find SSTOT,SSBET, andSSW and check thatSSTOT =SSBET +SSW. (Round your answers to threedecimal places.)
Find d.f.BET,d.f.W,MSBET, andMSW. (Round your answers forMSBET, and MSW totwo decimal places.)
Find the value of the sample F statistic. (Round youranswer to two decimal places.)
What are the degrees of freedom?
(c) Find the P-value of the sample test statistic.
P-value > 0.1000.050 < P-value <0.100Â Â Â Â Â 0.025 < P-value <0.0500.010 < P-value < 0.0250.001 <P-value < 0.010P-value < 0.001
(d) Based on your answers in parts (a) to (c), will you reject orfail to reject the null hypothesis?
Since the P-value is greater than the level ofsignificance at α = 0.01, we do not rejectH0.Since the P-value is less than orequal to the level of significance at α = 0.01, we rejectH0.     Since theP-value is greater than the level of significance atα = 0.01, we reject H0.Since theP-value is less than or equal to the level of significanceat α = 0.01, we do not reject H0.
(e) Interpret your conclusion in the context of theapplication.
At the 1% level of significance there is insufficient evidenceto conclude that the means are not all equal.At the 1% level ofsignificance there is sufficient evidence to conclude that themeans are all equal.     At the 1% levelof significance there is insufficient evidence to conclude that themeans are all equal.At the 1% level of significance there issufficient evidence to conclude that the means are not allequal.
(f) Make a summary table for your ANOVA test. (Round your answersfor SS to three decimal places, your MS and F Ratio to twodecimal places, and your P-value to four decimalplaces.)
Source of Variation | Sum of Squares | Degrees of Freedom | MS | F Ratio | P-Value | Test Decision |
Between groups | | | | | ---Select--- p-value > 0.100 0.050 < p-value < 0.1000.025 < p-value < 0.050 0.010 < p-value < 0.025 0.001< p-value < 0.010 p-value < 0.001 | ---Select--- Reject H0. Do not reject H0. |
Within groups | | | | | | |
Total | | | | | | |