The group consits of 105's and a 175 AP, by changing the settings for the group is this applied to all AP's in the group?
That is correct this will applied to all the APs in that group
Also I can't find the page exactly as discribed, attached is a screenshot
That's the correct page
Min EIRP and Max EIRP will the range of power levels arm can assign your APs
you can confirm the power levels by running the following command:
show ap active | include <name of the AP>
show ap arm rf-summary ap-name <name of the AP>
Why are you trying to change the power settings?