An observational study gathered data on the rate of progression of multiple scle
ID: 2957881 • Letter: A
Question
An observational study gathered data on the rate of progression of multiple sclerosis in patients diagnosed with the disease at different ages. Difference in the mean rate of progression were test among several groups that differed by age of diagnosis using ANOVA. The results gave a significance level of P= 0.12. From the following list, choose all of the correct conclusions that follow from this result. Explain the basis of your answer.
a) The mean rate of progression does not differ among age groups.
b) The study has failed to show a difference among means of age groups, but the existence of a difference cannot be ruled out.
c) If a difference among age groups exists, then it is probably small.
d) If the study had included a larger sample size it probably would have detected a significant difference among age groups.
Explanation / Answer
Since P - value, i.e. 0.12 is considerably large, we can conclude that, a) The mean rate of progression does not differ among age groups.