Question

Use this scenario for the next few questions.

Time spent with patients is an important variable to measure when running a doctor's office. Time spent with patients ((in minutes) was collected for 4 physicians within a practice.

> fit<-aov(Time~factor(Physician))
> summary(fit)
Df Sum Sq Mean Sq F value Pr(>F)
factor(Physician) ? 212.3 70.78 3.497 0.031
Residuals 24 485.8 20.24

1.

For the ANOVA that was run, what is the null hypothesis?

Group of answer choices

mean time spent in with patients is the same for all physicians

mean time spent with patients is different for all physicians

mean time is higher for physician 2

mean time is different for at least one physician

2.

For the ANOVA that was run, what is the alternative hypothesis?

Group of answer choices

mean time spent in with patients is the same for all physicians

mean time spent with patients is different for all physicians

mean time is higher for physician 2

mean time is different for at least one physician

3.

What are the degrees of freedom for "Physician"?

Group of answer choices

1

2

3

4

25

4.

Why was the code factor(Physician) used rather than just Physician in the fitted model statement?

Group of answer choices

This indicates "Physician" is the predictor

This indicates the column consisted of words, but should be treated as a categorical variable

This indicates the column consisted of numbers, but is to be treated like a categorical variable

Answer 1

1.null hypothesis H₀:mean time spent in with patients is the same for all physicians()

2.alternative hypothesis H₁:mean time spent with patients is different for all physicians()

3. we know,

df=3

hence,degrees of freedom for "Physician"=3

4. Fitting a model means that you're making your algorithm learn the relationship between predictors and outcome so that you can predict the future values of the outcome.  

hence, if code factor(Physician) used rather than just Physician in the fitted model statement. This indicates "Physician" is the predictor

please rate my answer and comment for doubts.