In: Statistics and Probability
In order to compare the life expectancies of three different brands of printers, four printers (sample size) of each brand were randomly selected. Information regarding the three brands is shown below. (60 points)
Brand A |
Brand B |
Brand C |
|
Sample mean: |
62 |
50 |
58 |
Sample variance |
36 |
25 |
32 |
a) State the null and alternative hypotheses to be tested. (10 points)
b) Complete ANOVA table below. The null hypothesis is to be tested at 95% confidence. You need to show the entire calculation process to get full credits. What do you conclude? (50 points)
SSTR =
MSTR =
SSE =
MSE =
F =
Critical value of F =
Summarize the final answers below.
Source of Variation |
SS |
df |
MS |
F |
F critical value |
Between Treatment |
|
||||
Within Treatment |
|
||||
Total |
|
do you need N value to solve this problem? no n value was given.