Settings

F4- 1/125 sec/ The background is not very visible
F5.6- 1/60 sec/ The background is sort of visible
F8- 1/60 sec/ The background becoming more visible
F11- 1/60 sec/ The background looks the same as the last setting
F16- 1/30 sec/ The background is visible.
F22- 1/8 sec/ The background is completely visible.

At slower shutter speeds, the subject(people) gets more blurry. To fix this, the photographer could make the shutter speed faster. The lowest shutter speed that can be held is probably around 1/15 sec.