# Help exam tomorrow!!

#### drbj

##### New Member
Need help for stats exam tomorrow!! I missed class the day this was covered so I have no idea how to calculate all this. Ps, my stats book is not helping.
The question is A small random sample of respondents has been selected to determine whether or not a city (N=5), a suburb (N=5), or rural (N=5) had attended in religious service differently.Respondents were asked to provide the number of times that they attended religious services in the previous month.
Sum of Squares
Between groups 11
Within groups 18

A.) Find the between groups mean square
B.) Find the within groups mean square
C.)Calculate the F ratio

#### Stats fan

##### Member
At the bottom of this web page you can find a table that shows how each entry of the ANOVA table is computed: http://www.statkat.com/stattest.php?t=11. As the table shows:
Mean square between = sum of squares between / degrees of freedom between
Mean square within = sum of squares within / degrees of freedom within
F = mean square between / mean square within

The degrees of freedom between is equal to the number of groups (in your case 3) minus 1
The degrees of freedom within is equal to the total sample size (in your case 15) minus the number of groups (in your case 3)

#### drbj

##### New Member
You are wonderful. Thank you so much!!!!