The times of first sprinkler activation for series of tests with fire prevention sprinkler systems using aqueous film forming were (in sec).
28 42 23 28 24 36 31 34 25 28 29 23 25
The system has been designed so that true average activation time, u is at most 25 sec under such conditions and is normally distributed. Does the data strongly contradict the validity of this design specification?
a. State the null hypothesis, H0.