Coffee, depression, and physical activity. Caffeine is the world\'s most widely
ID: 3259402 • Letter: C
Question
Coffee, depression, and physical activity.
Caffeine is the world's most widely used stimulant, with approximately 80% consumed in the form of coffee. Participants in a study investigating the relationship between coffee consumption and exercise were asked to report the number of hours they spent per week on moderate (e.g., brisk walking) and vigorous (e.g., strenuous sports and jogging) exercise. Based on these data the researchers estimated the total hours of metabolic equivalent tasks (MET) per week, a value always greater than 0. The table below gives summary statistics of MET for women in this study based on the amount of coffee consumed.
(a) Write the hypotheses for evaluating if the average physical activity level varies among the different levels of coffee consumption.
The mean MET for each group is equal to each other.
Null hypothesis
Alternative hypothesis
At least one pair of means is different.
Null hypothesis
Alternative hypothesis
(b) Below is part of the output associated with this test. Fill in the empty cells.
(c) What is the conclusion of the test?
The data _____ provide convincing evidence that the average MET differs between at least one pair of groups.
do
do not
Explanation / Answer
a)
H0: There is no significance difference among the different levels of coffee consumption.
H1: There is significance difference among the different levels of coffee consumption.
i.e. there is significance difference atlast one pair of means different
b)
c) Here P-value < alpha 0.05, so we reject H0
Thus The data do provide convincing evidence that the average MET differs between at least one pair of groups.
ANOVA Table Alpha = 0.05 Sum of Mean sum of Source df Squares Square F-Ratio F-crit P-Value Treatment 4 10507.81 2626.9525 5.21335332 2.372107 0.000339 Error 50735 25564819 503.8892124 Total 50739 25575327