knitr::include_graphics("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/pdf2png/lab 3/lab 3-1.png")

knitr::include_graphics("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/pdf2png/lab 3/lab 3-2.png")

knitr::include_graphics("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/pdf2png/lab 3/lab 3-3.png")

knitr::include_graphics("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/pdf2png/lab 3/lab 3-4.png")

knitr::include_graphics("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/pdf2png/lab 3/lab 3-5.png")

Question 1

i. Two conditions of balanced incomplete block design

a) All pairs of treatments occur together within a block an equal number of times.

b) Any treatment p-value < α = 0.05 is significant in treatment comparison.

ii. Response variable : The strength of the paper produced

iii. Treatment factor : Hardwood concentrations

iv. List treatments: 2,4,6,8,10,12,14

library(readr)
## Warning: package 'readr' was built under R version 4.0.5
datalab3<- read_csv("C:/Users/ADMIN/Downloads/UMP SEM 5/EDA/datalabreport3.csv")
## Rows: 21 Columns: 3
## -- Column specification --------------------------------------------------------
## Delimiter: ","
## dbl (3): Hardwood, Days, Strength
## 
## i Use `spec()` to retrieve the full column specification for this data.
## i Specify the column types or set `show_col_types = FALSE` to quiet this message.
datalab3
## # A tibble: 21 x 3
##    Hardwood  Days Strength
##       <dbl> <dbl>    <dbl>
##  1        2     1      114
##  2        2     5      120
##  3        2     7      117
##  4        4     1      126
##  5        4     2      120
##  6        4     6      119
##  7        6     2      137
##  8        6     3      117
##  9        6     7      134
## 10        8     1      141
## # ... with 11 more rows
Treatment = as.factor(datalab3$Hardwood)
block = as.factor(datalab3$Days)

Question 4

results = aov(Strength~block+Treatment,datalab3)
summary(results)
##             Df Sum Sq Mean Sq F value  Pr(>F)   
## block        6 1114.3  185.71   8.814 0.00358 **
## Treatment    6 1317.4  219.57  10.420 0.00205 **
## Residuals    8  168.6   21.07                   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1

a) H0: All population means are equal @ no treatments effect

H1: At least one of the population means is different @ there is treatment effects

p-value=0.0021

b) Since p-value=0.0021<alpha=0.05, reject H0.

c) At alpha=0.05, At least one of the population means is different @ there is treatment effects

d) Comparison of treatments

Tukey’s test

TukeyHSD(results)
##   Tukey multiple comparisons of means
##     95% family-wise confidence level
## 
## Fit: aov(formula = Strength ~ block + Treatment, data = datalab3)
## 
## $block
##              diff        lwr       upr     p adj
## 2-1  7.000000e+00  -7.309004 21.309004 0.5452172
## 3-1 -5.000000e+00 -19.309004  9.309004 0.8200632
## 4-1  1.800000e+01   3.690996 32.309004 0.0145450
## 5-1 -4.263256e-14 -14.309004 14.309004 1.0000000
## 6-1 -3.000000e+00 -17.309004 11.309004 0.9782633
## 7-1 -1.000000e+00 -15.309004 13.309004 0.9999467
## 3-2 -1.200000e+01 -26.309004  2.309004 0.1115313
## 4-2  1.100000e+01  -3.309004 25.309004 0.1575900
## 5-2 -7.000000e+00 -21.309004  7.309004 0.5452172
## 6-2 -1.000000e+01 -24.309004  4.309004 0.2210906
## 7-2 -8.000000e+00 -22.309004  6.309004 0.4149066
## 4-3  2.300000e+01   8.690996 37.309004 0.0032020
## 5-3  5.000000e+00  -9.309004 19.309004 0.8200632
## 6-3  2.000000e+00 -12.309004 16.309004 0.9972844
## 7-3  4.000000e+00 -10.309004 18.309004 0.9217599
## 5-4 -1.800000e+01 -32.309004 -3.690996 0.0145450
## 6-4 -2.100000e+01 -35.309004 -6.690996 0.0057301
## 7-4 -1.900000e+01 -33.309004 -4.690996 0.0105800
## 6-5 -3.000000e+00 -17.309004 11.309004 0.9782633
## 7-5 -1.000000e+00 -15.309004 13.309004 0.9999467
## 7-6  2.000000e+00 -12.309004 16.309004 0.9972844
## 
## $Treatment
##             diff         lwr        upr     p adj
## 4-2     3.000000 -11.3090041 17.3090041 0.9782633
## 6-2    11.666667  -2.6423374 25.9756707 0.1252127
## 8-2    18.000000   3.6909959 32.3090041 0.0145450
## 10-2   20.333333   6.0243293 34.6423374 0.0070052
## 12-2    5.666667  -8.6423374 19.9756707 0.7332911
## 14-2    9.000000  -5.3090041 23.3090041 0.3060975
## 6-4     8.666667  -5.6423374 22.9756707 0.3397085
## 8-4    15.000000   0.6909959 29.3090041 0.0394390
## 10-4   17.333333   3.0243293 31.6423374 0.0180585
## 12-4    2.666667 -11.6423374 16.9756707 0.9877953
## 14-4    6.000000  -8.3090041 20.3090041 0.6867666
## 8-6     6.333333  -7.9756707 20.6423374 0.6393680
## 10-6    8.666667  -5.6423374 22.9756707 0.3397085
## 12-6   -6.000000 -20.3090041  8.3090041 0.6867666
## 14-6   -2.666667 -16.9756707 11.6423374 0.9877953
## 10-8    2.333333 -11.9756707 16.6423374 0.9938365
## 12-8  -12.333333 -26.6423374  1.9756707 0.0993180
## 14-8   -9.000000 -23.3090041  5.3090041 0.3060975
## 12-10 -14.666667 -28.9756707 -0.3576626 0.0442095
## 14-10 -11.333333 -25.6423374  2.9756707 0.1405131
## 14-12   3.333333 -10.9756707 17.6423374 0.9644345
plot(TukeyHSD(results))

Based on the output, the significants are 8-2, 10-2, 8-4, 10-4, 12-10 because it has p-value < α=0.05.

The most significant comparison is 10-2 because it has the smallest p-value= 0.0070 and the largest difference.