In: Statistics and Probability
The following data are from a completely randomized design. In the following calculations, use
α = 0.05.
Treatment 1 |
Treatment 2 |
Treatment 3 |
|
---|---|---|---|
62 | 82 | 69 | |
46 | 73 | 53 | |
53 | 89 | 61 | |
39 | 60 | 45 | |
xj |
50 | 76 | 57 |
sj2 |
96.67 | 156.67 | 106.67 |
(a)
Use analysis of variance to test for a significant difference among the means of the three treatments.
State the null and alternative hypotheses.
H0: μ1 ≠
μ2 ≠ μ3
Ha: μ1 =
μ2 = μ3
H0: μ1 = μ2 = μ3
Ha: Not all the population means are equal.
H0: Not all the population means are
equal.
Ha: μ1 =
μ2 = μ3
H0: At least two of the population means are equal.
Ha: At least two of the population means are different.
H0: μ1 =
μ2 = μ3
Ha: μ1 ≠
μ2 ≠ μ3
Find the value of the test statistic. (Round your answer to two decimal places.)
Find the p-value. (Round your answer to three decimal places.)
p-value =
State your conclusion.
Reject H0. There is sufficient evidence to conclude that the means of the three treatments are not equal.
Reject H0. There is not sufficient evidence to conclude that the means of the three treatments are not equal.
Do not reject H0. There is sufficient evidence to conclude that the means of the three treatments are not equal.
Do not reject H0. There is not sufficient evidence to conclude that the means of the three treatments are not equal.
(b)
Use Fisher's LSD procedure to determine which means are different.
Find the value of LSD. (Round your answer to two decimal places.)
LSD =
Find the pairwise absolute difference between sample means for each pair of treatments.
[x1 − x2]
=
[x1 − x3 ]
=
[x2 − x3]
Which treatment means differ significantly? (Select all that
apply.)=
There is a significant difference between the means for treatments 1 and 2.
There is a significant difference between the means for treatments 1 and 3.
There is a significant difference between the means for treatments 2 and 3.
There are no significant differences.
Applying one way ANOVA: (use excel: data: data analysis: one way ANOVA: select Array): |
Source | SS | df | MS | F |
Between | 1448.00 | 2 | 724.000 | 6.033 |
Within | 1080.00 | 9 | 120.0000 | |
Total | 2528.00 | 11 |
a)
H0: μ1 = μ2 = μ3
Ha: Not all the population means are equal.
value of the test statistic F =6.03
p value =0.022
Reject H0. There is sufficient evidence to conclude that the means of the three treatments are not equal.
b)
critical value of t with 0.05 level and N-k=9 degree of freedom= | tN-k= | 2.262 | |||
Fisher's (LSD) for group i and j =(tN-k)*(sp*√(1/ni+1/nj) = | 17.52 |
Difference | Absolute Value | Conclusion |
x1-x2 | 26.00 | significant difference |
x3-x1 | 7.00 | not significant difference |
x3-x2 | 19.00 | significant difference |
There is a significant difference between the means for treatments 1 and 2.
There is a significant difference between the means for treatments 2 and 3.