Mean dry weights (mg) of 3 genotypes of beetles T. castaneum reared at a density
ID: 3173555 • Letter: M
Question
Mean dry weights (mg) of 3 genotypes of beetles T. castaneum reared at a density of 20 beetles per g of flour. There are 4 series of experiments that represent blocks.
Blocks = 4
Genotypes = 3
Replication = 3 groups of beetles per treatment per block
Fill in the following ANOVA table based on the information above.
Source
df
SS
MS
F-ratio Est P-val
RCBD
Treatment
0.009717
(with replication)
Blocking factor
0.021391
TxB
0.004181
Error
0.01392
Total
.049209
Is there a treatment effect?
Is there a block effect?
Is there an interaction?
In 1-2 sentences, explain these findings.
A plant ecologist wishes to test the hypothesis that the height of plant species X depends on the type of soil it grows in. He measures the height of 3 plants (in cm) in each of 4 plots representing different soil types. All four plots are contained in a 2-mile square area.
Create an ANOVA table, show your work when calculating the sums of squares.
Give your analysis of the null hypothesis that there is no difference in the growth in different soil types. Explain your findings in one sentence.
Observation
Plot A
Plot B
Plot C
Plot D
1
15
25
17
10
2
9
21
23
13
3
4
19
20
16
Source
df
SS
MS
F-ratio Est P-val
RCBD
Treatment
0.009717
(with replication)
Blocking factor
0.021391
TxB
0.004181
Error
0.01392
Total
.049209
Explanation / Answer
1)
1) For Treatments:
Since p >0.05 we do not reject the H0. Hence treatments are not significant'
2) for blocks
Since p < 0.05 we do reject the H0. Hence blocks are significant'
3) Interactions:
Since p >0.05 we do not reject the H0. Hence interactions are not significant'
part B)
H0: There is no difference between means of four groups
H1:There is a difference between means of four groups
alpha:5%
Test statistic:
From Excel
F cal=7.044
Conclusion:
P value= 0.0123
P < 0.05 we reject the H0. Hence claim is significant
df SS MS F-ratio Est Source P value Treatments 3-1=2 0.00097 0.00049 0.80136494 0.460852748 Blocking factor 4-1=3 0.021391 0.00713 11.7814416 7.07172E-05 TxB 2*3=6 0.004181 0.0007 1.15137692 0.36543633 Error 23 0.01392 0.00061 Total 36-1=35 0.049209