Question

Four different types of insecticides are used on strawberry plants. The number of strawberries on each randomly selected plant is given below. Find the test statistic F to test the hypothesis that the type of insecticide makes no difference in the mean number of strawberries per plant. Use α = 0.01.

Insecticide 1	Insectiside 2	Insecticide 3	Insecticide 4
6	5	6	3
5	8	3	5
6	5	4	3
7	5	2	4
7	5	3	4
6	6	3	5

STEP 1: Hypothesis: Ho:______________________________________ H1:______________________________________

STEP 2: Restate the level of significance: _______________________

STEP 4: p-value __________________________ from appropriate test on calculator.

STEP 5: Conclusion.

Answer 1

Here we will perform the one way anova, we use the R software for performing anova which is free software. The R-codes for preforming the analysis is given below along with output

>data=read.csv(file.choose())

>attach(data)

>owanova<-aov(strawaberries~as.factor(insecticide), qr=TRUE)

One-Way ANOVA
	df	Sum of Squares	Mean Squares	F	Pr(>F)
insecticide	3	29.66666667	9.88888889	8.35680751	0.00084575
Residuals	20	23.66666667	1.18333333	NA	NA

STEP 1: Hypothesis: Ho: The type of insecticide makes no difference in the mean number of strawberries per plant.

H1: The type of insecticide makes difference in the mean number of strawberries per plant.

STEP 2: Restate the level of significance: 0.05, i.e., 5%

STEP 4: p-value 0.0008457 from appropriate test on calculator.

STEP 5: Conclusion: here the p-value is less than 5% level of significance. Therefore we may reject the null hypothesis at 5% level of significance. And the conclude that, the type of insecticide may be makes difference in the mean number of strawberries per plant.