Thursday, October 31, 2019

Problem 11.12 from book R Printout. Individual Group Mean CIs plus Tukey Procedure

> ex1112
# A tibble: 12 × 2
    Time Program
   <dbl>   <dbl>
1     59       1
2     64       1
3     57       1
4     62       1
5     52       2
6     58       2
7     54       2
8     58       3
9     65       3
10    71       3
11    63       3
12    64       3

> lm12=aov(Time~as.factor(Program),data=ex1112)
> anova(lm12)

Analysis of Variance Table

Response: Time

                   Df Sum Sq Mean Sq F value  Pr(>F)  
as.factor(Program)  2 170.45  85.225  5.7042 0.02512 *
Residuals           9 134.47  14.941                  
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

> lsmeans(ls.lm12,"Program")

 Program   lsmean       SE df lower.CL upper.CL
       1 60.50000 1.932663  9 56.12801 64.87199
       2 54.66667 2.231647  9 49.61833 59.71500
       3 64.20000 1.728626  9 60.28958 68.11042

Confidence level used: 0.95



> ls.lm12 <- update(ls.lm12, by.vars = NULL, level = 0.99)
> lsmeans(ls.lm12,"Program")
 Program   lsmean       SE df lower.CL upper.CL
       1 60.50000 1.932663  9 54.21916 66.78084
       2 54.66667 2.231647  9 47.41418 61.91915
       3 64.20000 1.728626  9 58.58225 69.81775


Confidence level used: 0.99 

> TukeyHSD(lm12)
  Tukey multiple comparisons of means
    95% family-wise confidence level

Fit: aov(formula = Time ~ as.factor(Program), data = ex1112)

$`as.factor(Program)`

         diff        lwr       upr     p adj
2-1 -5.833333 -14.075867  2.409201 0.1738314
3-1  3.700000  -3.539501 10.939501 0.3684099
3-2  9.533333   1.651963 17.414703 0.0201421

> plot(TukeyHSD(lm12))