The strenght of five types A, B, C, D and E of fibre-boardwere being compared. 4

Question

The strenght of five types A, B, C, D and E of fibre-boardwere being compared. 4 boards of each type were tested. The modulusof rupture of each of the 20 boards is given in the followingtable:          A            B            C            D            E       619         424         392        462        465          674         525         494       559         568        633         549         441         556        613       622         601         457         611        611 a) Use Barlett's test to determine if the within boardvariances are significantly different (=0.05). b) Perform analysis of variance and draw your conclusions(=0.05). c) Use Duncan's New Multiple Range Test, with a 0.05 level ofsignificance to compute the means. Discuss your results. d) Calculate 95% confidence limits for the difference of meansD and E The strenght of five types A, B, C, D and E of fibre-boardwere being compared. 4 boards of each type were tested. The modulusof rupture of each of the 20 boards is given in the followingtable:          A            B            C            D            E       619         424         392        462        465          674         525         494       559         568        633         549         441         556        613       622         601         457         611        611 a) Use Barlett's test to determine if the within boardvariances are significantly different (=0.05). b) Perform analysis of variance and draw your conclusions(=0.05). c) Use Duncan's New Multiple Range Test, with a 0.05 level ofsignificance to compute the means. Discuss your results. d) Calculate 95% confidence limits for the difference of meansD and E

Explanation / Answer

Test for Equal Variances:strengths versus types

95% Bonferroni confidenceintervals for standard deviations

types N    Lower    StDev   Upper
    1 4 12.2737 25.3903 164.211
    2 4 35.9074 74.2804 480.407
    3 4 20.4444 42.2926 273.527
    4 4 29.9892 62.0376 401.227
    5 4 33.5222 69.3464 448.496

Bartlett's Test (normal distribution)
Test statistic =3.27, p-value = 0.514

One-way ANOVA: strengths versustypes

S = 57.63   R-Sq =60.45%   R-Sq(adj) = 49.91%

                        Individual 95% CIs For Mean Based on
                        Pooled StDev
Level N    Mean StDev --+---------+---------+---------+-------
1      4 637.00 25.39                         (-------*------)
2      4 524.75 74.28           (-------*------)
3      4 446.00 42.29 (-------*------)
4      4 547.00 62.04              (------*-------)
5      4 564.25 69.35                (-------*------)
                        --+---------+---------+---------+-------
                        400      480      560       640

Pooled StDev = 57.63

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.