A researcher wants to determine the impact of soil type on the growth of a certa
ID: 3156458 • Letter: A
Question
A researcher wants to determine the impact of soil type on the growth of a certain type of plant. She grows three plants in each of four different types of soil and measures the growth in inches for each plant after one month resulting in the data below.
a) What null hypothesis is the researcher testing if she runs an ANOVA with this data?
Soil 3 provides a lower mean growth for the plant than the other types of soil.
The mean growth of the plant in each type of soil is the same.
One type of soil has a higher mean growth for the plant than the others.
The mean growth of the plant is different in each type of soil.The variability in growth of the plant in each type of soil is the same.
b) What is the SStrt for the ANOVA? Give your answer to at least three decimal places.
c) What is DFerr for the ANOVA?
d) What is the value of the F statistic for the ANOVA? Give your answer to at least three decimal places.
e) Using a 0.05 level of significance, what conclusion should the researcher reach?
The mean growth of the plant is not the same for all soil types.
Soil 3 has a lower mean growth for the plant than the other types of soil.
Soil 1 has a higher mean growth for the plant than the other types of soil.
There is not enough evidence to reject the claim that the mean growth of the plant is the same in each type of soil.
Explanation / Answer
The ANOVA Table is
a. The null hypothesis is,
b. The SStrt for the ANOVA is 20.5067
c. The DFerr for the ANOVA is 11.
d. The value of the F statistic for the ANOVA is 11.2417.
e. Corresponding p-value = 0.007 < 0.05, hence we reject the null hypothesis and conclude that atleast one type of soil has a higher mean growth for the plant than the others.
ANOVA Source of Variation SS df MS F P-value F crit Rows 2.1717 2 1.0858 1.7857 0.2463 5.1433 Columns 20.5067 3 6.8356 11.2417 0.0071 4.7571 Error 3.6483 6 0.6081 Total 26.3267 11Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.