Questions: Recent research indicates that the effectiveness of antidepressant medication is directly related to the severity of the depression (Khan, Brodhead, Kolts Brown, 2005). Based on pretreatment depression scores, patients were divided into four groups based on their level of depression. After receiving the antidepressant medication, depression scores were measured again and the amount of improvement was recorded for each patient. The following data are similar to the results of the study.
Low Moderate High Moderate Moderately Severe Severe 3.3 1 3.8 3.2 1.3 2.5 1.7 1.8 1 2.2 5.4 5.2 0.5 2.8 3.8 3.5 3.6 2.8 2.4 4.9 0 2.5 3.5 3.4
From this table, conduct an one-way ANOVA. Calculate the F-ratio and p-value. Be sure to round your answers to three decimal places. Assume all population and ANOVA requirements are met.
F-ratio:
p-value:
Transcript text: Recent research indicates that the effectiveness of antidepressant medication is directly related to the severity of the depression (Khan, Brodhead, Kolts & Brown, 2005). Based on pretreatment depression scores, patients were divided into four groups based on their level of depression. After receiving the antidepressant medication, depression scores were measured again and the amount of improvement was recorded for each patient. The following data are similar to the results of the study.
Low Moderate High Moderate Moderately Severe Severe 3.3 1 3.8 3.2 1.3 2.5 1.7 1.8 1 2.2 5.4 5.2 0.5 2.8 3.8 3.5 3.6 2.8 2.4 4.9 0 2.5 3.5 3.4
From this table, conduct an one-way ANOVA. Calculate the $F$ -ratio and $p$-value. Be sure to round your answers to three decimal places. Assume all population and ANOVA requirements are met.
F-ratio: $\square$
$p$-value: $\square$
Solution
Solution Steps
Step 1: Calculate Sum of Squares
The total sum of squares between groups is calculated as follows: